Talk:Milky Way/Archive 5

Relative size visualization is incorrect
This statement in the Size and mass section has two problems:

Alternatively visualized, if the Solar System out to Pluto were the size of a US quarter (25 mm in diameter), the Milky Way would have a diameter of 2,000 kilometers, an area approximately one third the size of the United States.

First of all, a diameter (one dimension) cannot be compared with an area (two dimensions). This could be fixed by changing area to length (or just dropping it entirely) and size to breadth or similar.

Secondly, it would still be wrong after such a change. That would make the breadth of the U.S. 6000 km, whereas 4300 km or so is closer to the mark, depending on where you measure it.

How about this (ignoring the planetary status of Pluto for now, and making it a little less U.S.-centric):

Alternatively visualized, if the Solar System out to Pluto were the size of a US quarter or 1-Euro coin (25mm, 23mm respectively), the Milky Way would have a diameter of 2,000 kilometers, or approximately half the breadth of the United States or Europe.

Mathglot (talk) 21:15, 9 September 2014 (UTC)


 * Had another look at this to check the math and it turns out that the original value of 2,000 km is correct, it's only the comparison to the U.S. that was wrong.


 * Based on an assumption of 11.8 billion km (11.8 * 10**9 km) for the average diameter (twice the radius) of Pluto's (highly elliptical) orbit, reducing that to 25mm is a reduction factor of 472 trillion. Reducing the Milky Way (diameter 9.46 * 10**17 km) by an equivalent amount yields a diameter of 2,004 km.  So that value looks okay.


 * Mathglot (talk) 23:10, 9 September 2014 (UTC)


 * Yet another problem: it appears that the WP editor who added the section on the size analogy and added a reference for it misinterpreted what was meant by "the Solar System" and mistakenly added the words "out to Pluto" in an apparent attempt to clarify this point.  Unfortunately, he got it wrong as the Solar System is measured to Neptune's orbit now and although the reference does not make this clear, the math does.
 * Further, the incorrect "one third" U.S. size claim in the WP article is not supported by the reference. In fact, the reference says:
 * "Imagine that our entire Solar System were the size of a quarter. ... On this scale, the diameter of our Milky Way galaxy will be about the size of the United States!"
 * This is, in fact, accurate using the recently adopted notion of the Solar System, i.e., out to the orbit of Neptune. Whoever added the words 'out to Pluto' in the WP article did not get them from the reference.  Would've been nice if the Smithsonian article had been more explicit about this, but given that the math for "about the size of the United States" requires a Solar System diameter of approximately Neptune's orbit, I'm changing the article to read thus:


 * Alternatively visualized, if the Solar System out to Neptune were the size of a US quarter (25mm), the Milky Way would have a diameter of 4,000 kilometers, or approximately the breadth of the United States.

Mathglot (talk) 19:48, 19 September 2014 (UTC)
 * This hews more closely to the reference, and is accurate.


 * I'm not aware of any source that states the Solar System only extends to the orbit of Neptune, which would be a diameter of ~60 AU. The Solar System is the Sun along with everything orbiting the Sun. The Oort cloud orbits the Sun, and if you counted it the diameter would be more like 100,000 AU. Primium mobile (talk) 14:43, 9 October 2014 (UTC)


 * You're quite correct about that as one definition of the solar system, but that doesn't affect the discussion above a jot, as we're talking about calculations based on what the sources say. Please reread it. Mathglot (talk) 09:56, 19 October 2014 (UTC)


 * I don't need to reread it. You're nitpicking the "out to Pluto" reference when it doesn't make any difference. The ratio of solar system diameter to Milky Way diameter, with the level of accuracy that is being used, is not going to change the result. We don't even know the exact diameter of the Milky Way. We have a 20,000 LY difference between the high and low estimates of the diameter. No one is even sure how to define the "edge" of the Milky Way. So, my point is that the rewording shouldn't say "out to Neptune" at all. It should just say "solar system" just like the original source states. When dealing with such large margins of error, just saying "solar system" instead of "solar system out to Neptune" is more than sufficient. Primium mobile (talk) 14:19, 22 October 2014 (UTC)


 * I really, really doubt that anyone other than experts can "visualize" the Solar System; the scale of distances is beyond normal human experience. Hence, any comparison of the "size" of the Solar System to that of the galaxy is going to be abstract. There is, imho, WAY TOO MUCH emphasis and 'ink' being used. You have, it seems to me, three reasonable measures of physical volume of the Solar System: to the heliopause, to the 'edge' of the Oort Cloud, or to Neptune's apogee. I suggest that rather than using a multitude of similar comparisons, you agree to choose ONE that is most understandable to the widest audience.216.96.76.190 (talk) 04:38, 11 December 2014 (UTC)


 * No, you also aren't getting what I am saying. We do not know how large the Milky Way is. We could be off by as many as 20,000 LY. The diameter Neptune's orbit is at right around .0013 LY. That is .0000065% of the margin of error on the diameter of the Milky Way. The Heliopause is right around .0032 LY in diameter. That is .000016% of the margin of error on the diameter of the Milky Way. Finally, the Oort Cloud is thought to start at about .8 LY. Even that is only .004% of the margin of error on the diameter of the Milky Way.


 * The point is that, no matter what measurement you use for the size of the Solar System, the differences are only a tiny fraction of the uncertainty in the size of the Milky Way. So we shouldn't be specific on what is meant by "Solar System" because that gives an answer with greater precision than the numbers you started with. Primium mobile (talk) 17:42, 16 December 2014 (UTC)


 * Granting everything you said about precision, margin of error and the illy-defined or uncertain boundaries of the solar system and the Milky Way, you still miss the point I'm afraid. If you reread the source (which I'm aware you already said you don't need to, nevertheless you do need to if you are to get the point) you would find a size analogy whose math is correct only for a solar system whose size equates to the diameter of the orbit of Neptune.  Regardless whether you're more correct about the Solar System being defined out to the Oort cloud or the heliopause or any other limit of your choosing, the math in the reference would be orders of magnitude off with the current analogy, given your definition.  It's clear that what they meant was the man-in-the-street version of the Solar System (and whether you choose Neptune or Pluto hardly matters much, as they intersect).  If you want to insist that the Solar System is 100,000 AU, fine, I have no problem with that, but then you'll need a new analogy and a new source containing it to back it up, as the current analogy cannot hold up with a 100,000 AU Solar System, as the math is way off. Now you see the point?

Mathglot (talk) 01:19, 31 January 2015 (UTC)


 * I see the point, and I don't need to reread the reference because that's not what I am talking about. I know what it says. What I am saying is that you can not get an answer with a greater order of precision than what you start with. It's not mathematically sound. Usually, if you divide two by three, you can assume that what you are doing is dividing 2.000000000000000... by 3.0000000000000... In this case, it's more like 2.0000000000001 divided by 3.00000000000089, and you arriving at .666... That's not the way math works. You are applying too great of a precision to the outcome when we don't know the input to any degree of precision at all. That's why I think this size reference should either be left intentionally vague or it should be removed from the article. You don't have to agree with that, and I'm not going to make any edits to contradict yours. I'm just telling you why I think you are wrong. Primium mobile (talk) 17:08, 27 February 2015 (UTC)

Problem with the Milky Way's description and size.
This article is tragically unclear about its subject. For instance, is the Milky Way the stellar (visible) disc or is it the gravitationally bound objects which include (as a minor part) its stars? In fact; its both, and more. Some use the term to refer to the disc, some to its visible star (systems), some include the (hydrogen) gas and dust, and some include the dark matter, while others include dwarf galaxies (& clusters) in our galactic neighborhood. If I was writing it, I'd start with the earliest understanding (band of light) move on more recent ones (the whole Universe) and then to the understanding that our galaxy is one of many, finally ending up with the idea that the Milky Way is a spherical cloud of dark matter which contains a disc of (orbiting) visible stars as well as smaller (dwarf) galaxies orbiting/attracted to it. I'd include estimates of its mass (total, stars (and planets), gas and dust, and dark matter, and black holes) and the fraction of those components NOT in the galactic disc. The various estimates of number of stars, length and thickness of the disc, and overall diameter could usefully be compiled in a table, I'd guess. I'd probably also include some discussion of the estimated number of various classes of stars (perhaps in another table) as well as the age distribution. Recent work (2014) estimates that up to half of the normal matter of the Milky Way is outside of the disc. I don't know if this work is widely accepted by the experts, buts its been peer reviewed/published (perhaps Science, IDK, but thats where I read about it). So, we believe the Milky Way first started 'forming' shortly after the Big Bang (first 10 million years). Last I heard, we're not sure which came first, population III stars (the first stars) or the Milky Way. We're also not sure when Sag A* got its start - was it a cause of the galaxy formation or a result? Its an active area of research/modeling. Then the most active star formation period, about 4 billion years ago and now we are in a large galaxy in its middle age, where most of the stars it will ever form, are already formed. We believe that in roughly 4 billion years we will collide with Andromeda. While that collision may change the orbits of most of the stars in both, it is likely that the two galaxies will generally 'pass through' each other with relatively few physical collisions between stars. As stars use up their fuel, the appearance of the Milky Way will change. Few stars will be created 10 billion years from now. I'd also mention that the majority of the Milky Way is NOT visible, rather it is obscured by its many dust clouds. IMHO, the fact that the spiral arms don't describe stable structures (long term persistence) as the individual stars orbit is also given short shrift here. I'd also mention that we have recently identified one star which possibly originated in the same cluster as the Sun. Since we expect we had hundreds of sibling stars, this discovery marks a exciting epoch in understanding how the Milky Way evolved over time.216.96.76.190 (talk) 05:18, 11 December 2014 (UTC)


 * So do that. No one is stopping you. Primium mobile (talk) 17:44, 16 December 2014 (UTC)


 * In my view the Milky Way refers to the luminous band across the sky caused by the light of stars in the disc of the Galaxy (and probably the Bulge too). The galaxy that the Solar System is part of is the Galaxy, which can reasonably be called the Milky Way Galaxy. To me Milky Way refers only to the Galactic disc and Bulge and the objects they contain. It does not refer to the stellar halo, the Galactic Centre or the dark matter halo. So, personally, I would have written two articles, one called The Galaxy or possibly The Milky Way Galaxy about the galaxy we live in, and another article called Milky Way about the luminous band across the sky. However, this would be a different perspective from the one used here on the English-language Wikipedia page, and from most of the other language Wikipedias I can half get the gist of. TowardsTheLight (talk) 09:48, 1 December 2015 (UTC)

Astronomical history
The estimation for the number of stars in milky way has seen a dramatic increase even in last 30 years. Therefore, astronomical history section of the article should contain past estimations, such as the ones mentioned here. Logos (talk) 19:11, 26 January 2015 (UTC)

Oldest known star
Something I'm working on tracking down: the article's treatment of the "oldest known star" is a bit of a mess. The infobox has one, the lede a second, the text a third, all of which are inconsistent and give no synthesized picture. (I'm sure this has arisen because each time there's a new study or press release that claims to have found the latest oldest known star, someone adds it in one place but not the others.) A review article or the introduction of a paper with some sort of summary would be best; I'll try to track one down. —Alex (Ashill &#124; talk &#124; contribs) 17:50, 16 March 2015 (UTC)

Old Disk Population
Various articles on Wikipedia use the term "old-disk star", but they don't explain it. Could that term&mdash;and/or old disk population&mdash;be covered somewhere in this article? It seems appropriate. Praemonitus (talk) 21:26, 20 March 2015 (UTC)

Sifting through the center of milky way galaxy
By observing and sifting through the center of milky way galaxy scientists have understood the importance of dust in formation of stars and planets. Continue reading here:

http://phys.org/news/2015-03-milky-center-unveils-supernova-factory.html

MansourJE (talk) 13:23, 24 March 2015 (UTC)

Units for angular momentum
Very simple: I want to look up the angular momentum of the Milky Way, and I find it listed with the units J s/rad. This may be the way some cognoscenti describe angular momentum, but I just want standard units, like J s. I don't want to have to read up on why it is divided by radians. — Preceding unsigned comment added by Ripetti (talk • contribs) 03:17, 2015 April 15 (UTC)
 * Hi, I urge you to take this question to reference desk. On talk pages we only discuss about how we can improve an article. Thank you! -- Chamith  (talk)  03:36, 15 April 2015 (UTC)
 * Actually, because it is not the normal unit in which angular momentum is expressed, this is appropriate to mention here. We should convert that unit to typically understood units, maybe alongside the value in its current unit. --JorisvS (talk) 07:53, 15 April 2015 (UTC)
 * When the unit is expressed as J s, it is implicitly J s/rad, since radians are dimensionless. Astronomers (and thus astronomy articles) often like to be explicit that the radian is hidden in there (and because astronomers will sometimes express angles with degrees, arcminutes, or arcseconds, depending on context). But 1 J s = 1 J s/rad. —Alex (Ashill &#124; talk &#124; contribs) 13:41, 15 April 2015 (UTC)
 * I know the rad is dimensionless, but it is still a meaningful unit, which can be seen from the conversion of rad/s to Hz. The formula for angular momentum is L=Iω, with I=[kg m2] and ω=[rad/s], so L=[kg m2 rad/s], which gives [J s rad], not [J s/rad]. Something isn't adding up. --JorisvS (talk) 14:19, 15 April 2015 (UTC)
 * (ec) I see that the cited source doesn't actually include the "/rad", so I removed it. (As noted, it doesn't change the number.) However, specifying one angular momentum for the Milky Way is a questionable exercise, as it depends entirely on the radius you choose. The cited source just uses it as a unit, not really in the context of the Milky Way, and I can't find any other source that gives a number. The closest I can find is Figure 7 of this paper, which plots angular momentum as a function of radius. But I can't find any other source that quotes the total angular momentum of the Milky Way. Given that the source we have is somewhat questionable, I'm not sure the angular momentum should be in the article at all. —Alex (Ashill &#124; talk &#124; contribs) 14:25, 15 April 2015 (UTC)

150-180 kly
The Milky Way is now know to be 150-180 kly, not 120kly. Please do not make ANY reversions to this without proper research AND discussing here. Do NOT vandalize the article by changing it back simply because you don't like change. It MUST be discussed. 66.190.94.33 (talk) 20:43, 1 June 2015 (UTC)


 * This is discussed in the lede of the article. You're changing the number in the infobox. The larger diameter is from one recent study (and accompanying press release and media coverage). It's better to be conservative until this is more widely confirmed when just reporting one number, with more detail and the latest result in the text. I did change the infobox to say "at least 100–120 kly". —Alex (Ashill &#124; talk &#124; contribs) 20:48, 1 June 2015 (UTC)
 * Fine with going this direction, but changed ambiguous "at least" 100ly to 100-180ly. Journal article has not yet been refuted, and this is actually follow-up research of research done many years ago. Large range is acceptable. 66.190.94.33 (talk) 21:05, 1 June 2015 (UTC)

Galactic Center - section needs an edit.
In the section, the sentence "In most galaxies, Wang et al. report, the rate of accretion of the supermassive black hole is slow, but the Milky Way seems to be an important exception." should be removed. I assume "Wang et al" is the current reference 93. There is nothing in that reference that directly makes that claim. Note that except for the abstract (and abstracts of editorial comments on the article), the article is behind a pay-wall (or membership in AAAS required). I assume this sentence was garbled from the free abstract:"Most supermassive black holes (SMBHs) are accreting at very low levels and are difficult to distinguish from the galaxy centers where they reside. Our own Galaxy’s SMBH provides an instructive exception ..." While you COULD argue that Wang is saying the Milky Way is an exception to the LOW (not "slow"!) rate of accretion, the body of the report contradicts that; for instance:"The x-ray emission of Sgr A* [represents] a common “inactive” state of galactic nuclei in the local universe." The explanation is that the Wikipedia contributor was who added this line didn't actually READ the article. The exception is that for our Milky Way, we CAN distinguish its supermassive black hole "from the galaxy centers where [it] reside[s]". The exception is simply due to our proximity to the galactic center (compared to our ability to spatially resolve x-ray spectra from other galaxies), and isn't noteworthy in this context, I think. The sentence should be removed. Note:I am an astrophysical layperson but I have read the article, in full, and all supplemental material.216.96.76.54 (talk) 20:56, 22 July 2015 (UTC)


 * Agreed. The sentence doesn't even belong in that paragraph; it should either be deleted or else be moved up to the previous discussion and changed to note that the SMBH is accreting mass at a level much lower than that of a normal active galaxy. (If I read it correctly, the current accretion rate is around 1 × 10−5 solar masses/year.) Praemonitus (talk) 00:25, 23 July 2015 (UTC)


 * ✅ Praemonitus (talk) 14:08, 24 July 2015 (UTC)

Sun's location and neighborhood
A pre-existing reference

The apex of the Sun's way, or the solar apex, is the direction that the Sun travels through space in the Milky Way. The general direction of the Sun's Galactic motion is towards the star Vega near the constellation of Hercules,

with similar references found here:

https://search.yahoo.com/search;_ylt=ApNVKq_VRUmxP6eOqEZI7rebvZx4?p=Sun%27s+Galactic+motion +is+towards+the+star+Vega+near+the+constellation+of+Hercules&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-901&fp=1

is conflicting with information I noticed in a 2014 article here:

http://news.nationalgeographic.com/news/2011/04/110407-sun-nose-scorpius-solar-system-nasa-ibex-ribbon-space-science/

which I added as the last sentence in the sub-header, as:

The Solar System is headed in the direction of the zodiacal constellation Scorpius, which follows the ecliptic.[145]

Someone should debate the contents and decide. Ncsr11 (talk) 19:49, 2 August 2015 (UTC)

Uses first person
The first paragraph of this article uses first person: "The Milky Way is the galaxy that contains our Solar System.[18][19][20][nb 1]"

Wikipedia's policy says not to use first person. Shouldn't this be fixed? --Proud User (talk) 00:21, 16 September 2015 (UTC)
 * Aside from being unencyclopedic wording as you've pointed out, as a proper name, "'our' Solar System" is even poor wording regardless of where it is written because there is only one Solar System, the Sun and its planetary system, so that "our" cannot specify it. It's like saying "our Earth", "our Moon", "our Mars", which are also fully unambiguous without it "Earth", "the Moon", "Mars". My experience when I tried to fix this was that there are a few people who apparently WP:OWN this particular wording. --JorisvS (talk) 22:52, 15 September 2015 (UTC)
 * This has been the subject of repeated discussion with no clear consensus, including a discussion (started in 2012) that is still on this talk page. Though I too prefer "the Solar System", I don't think that using the first person in this context is unacceptable; "our" is true for every conceivable reader (human or not!) of this article. In particular, the policy cited says that first person is ok in scientific writing, which I think applies here. The prohibition on first person is to prevent basing Wikipedia on "one person's opinions or experiences", which isn't a concern here. And "our Solar System" is certainly a common usage in reliable sources, even though I agree that it is properly redundant (though, as noted in the previous discussion, "solar system" is commonly used to refer to other stellar and planetary systems). —Alex (Ashill &#124; talk &#124; contribs) 23:38, 15 September 2015 (UTC)
 * Note that "solar system" is, but "Solar System" isn't. With the difference the same as between "Moon" and "moon". It would be technically correct to say "The Solar System is our solar system.". --JorisvS (talk) 23:44, 15 September 2015 (UTC)
 * I concur, though "our Solar System" is still common usage in sources. Not a usage I would write unless forced to by a misguided style guide (or Wikipedia consensus), though. —Alex (Ashill &#124; talk &#124; contribs) 23:51, 15 September 2015 (UTC)

As Ashill pointed out there is voluminous talk on this, all you need to do is scroll up. The guideline being cited does not make the claim "never use our", it says "Wikipedia articles must not be based on one person's opinions or experiences".....errr, living in this solar system is everyone's opinion or experience, no exceptions. Claims "there is only one Solar System" do not hold water, scroll up for that old argument. Fountains of Bryn Mawr (talk) 03:50, 16 September 2015 (UTC)
 * Not at all. So far, no one has been able to successfully argue that there are multiple "Solar Systems" with capital Ss (which you apparently claim, saying 'Claims "there is only one Solar System" do not hold water'), and hence why "the Solar System" is supposed to be ambiguous wording. You want to give it a shot? --JorisvS (talk) 09:36, 16 September 2015 (UTC)
 * I have found that it possiblie not to use the word "our" though, because Wikipedia's article on the Solar System itself avoids that word and so do dictionaries.--Proud User (talk) 09:43, 16 September 2015 (UTC)
 * No one doubts that it's possible to not use "our". It's just that there was a long discussion in 2012, and "our" won the day (though, rereading the discussion, I wouldn't say a consensus was reached). Personally, my order of preference remains "Earth" > "the Solar System" > "our Solar System" > "the Sun", though I would consider any of those options just fine. I don't think there's any policy or reference that prefers any one of these; it's just a writing choice. In a case like this, we can't use every editor's first choice. —Alex (Ashill &#124; talk &#124; contribs) 15:23, 16 September 2015 (UTC)
 * The problem with the word "our" is that it is biased towds those who live in the Milky Way and therefore violates WP:NPOV.--Proud User (talk) 18:42, 16 September 2015 (UTC)
 * Sorry, that argument is incorrect. If you actually read WP:NPOV, it says (emphasis added) "content on Wikipedia must be written from a neutral point of view (NPOV), which means representing... all of the significant views that have been published by reliable sources on a topic." I'm not aware of any reliable sources that have published views from outside the Solar System (or our Solar System). We need to be neutral with respect to non-FRINGE views and perspectives, not neutral with respect to life outside the Solar System. Nonsense policy arguments like this weaken the proper case for "the Solar System", which I think is simply better writing than "our Solar System". —Alex (Ashill &#124; talk &#124; contribs) 19:03, 16 September 2015 (UTC)
 * I should have said "less neutral than it could be." I would also like to point out that the article on Earth doesen't use words like "our," even though all reliable sources about the Earth is written by someone who lives there.--Proud User (talk) 20:00, 16 September 2015 (UTC)
 * .....to boil it down: Earth or Solar System are well known concepts or easily defined by the what they include (so no need for any possessive). We do not have that luxury with "Milky Way", it would be very foolish to assume the reader knows we live there so that part of its encyclopedic description needs to be mentioned in the first sentence. The chosen method so far is "our". Fountains of Bryn Mawr (talk) 20:46, 16 September 2015 (UTC)
 * We could say Earth's solar system rather than our solar system. If you scroll to the top of the page you will see argument about weather to say "the Earth" or the "Solar System," but saying Earth's solar system will make use of both words.--Proud User (talk) 23:54, 16 September 2015 (UTC)
 * Same problem as above, the Earth does not have a solar system, the Sun does. And its an arbitrary stopping point for no good reason - it slides down to us --> our solar system. Fountains of Bryn Mawr (talk) 01:55, 17 September 2015 (UTC)
 * We could say something like "the solar system of Earth's (sun/star.)--Proud User (talk) 10:17, 17 September 2015 (UTC)
 * This is just a repetition of the talk above with no obvious change in consensus and I think we have enough discussion on three letters (again agreeing with Ashill). Fountains of Bryn Mawr (talk) 13:54, 17 September 2015 (UTC)
 * However, "Earth" is, in the sentence, a modifier of the word "Solar System," so "Earth" is not the primary topic of the sentence as the disscusion above is concerned about.--Proud User (talk) 18:45, 17 September 2015 (UTC)
 * It does. Earth is part of a solar system, which is then logically Earth's. --JorisvS (talk) 10:12, 17 September 2015 (UTC)
 * I'll also mention that mentioning the Solar System in this article serves a very different purpose than in Solar System. Here, it's just to say that we care about the Milky Way more than any other single galaxy because it's the galaxy that we happen to be in; in that context, the word "our" isn't crazy. (That was the crux of my argument in 2012 that "Earth" is a better choice than either "the Solar System" or "our Solar System".) In the Solar System article, the whole focus is on the Solar System, so the reason for mentioning it isn't a point of emphasis about our location. By the way, all 13 of the other mentions of the Solar System in Milky Way call it "the Solar System", since the point isn't to emphasize that we live in the Milky Way. Again, I prefer "the Solar System", but there is a self-consistent logic to having the article the way it is. (I think this may be enough discussion on three letters!) —Alex (Ashill &#124; talk &#124; contribs) 19:10, 16 September 2015 (UTC)
 * But there isn't more than one Solar System. There is no point in using "our", as it can actually make people think that there are other "solar systems". AYFKM (talk) 22:20, 11 January 2016 (UTC)

"there isn't more than one Solar System", care to offer a citation?. As far as other people are concerned, there is more than one solar system, which is why we explain. Fountains of Bryn Mawr (talk) 20:17, 12 January 2016 (UTC)
 * I agree, every instance of planets orbiting a star is a Solar System, which means there are probably millions of "Solar Systems" in our galaxy alone, which are not ours.   Mlpearc  ( open channel ) 20:28, 12 January 2016 (UTC)
 * Other "solar systems" are called planetary systems; look at the first line of the article. Almost always, "solar" refers to our Sun, and only our Sun ("solar" comes from "Sol", meaning "Sun" in Latin. ) — for example, particles shot from the Sun are called solar winds. Particles shot from other stars are called stellar winds. Solar astronomy is the study of the Sun; stellar astronomy is the study of stars in general. Heck, the nebula from which the Sun formed is often called "the solar nebula". I could go on and on, but there is essentially no case where "solar" refers to another star, unless used informally. AYFKM (talk) 18:19, 13 January 2016 (UTC)
 * Could you please "go on and on" with citations? Cite clear guidance from multiple authoritative sources that out rank Websters as to "what is called a solar system" and you actually don't have to go on and on. Fountains of Bryn Mawr (talk) 19:53, 13 January 2016 (UTC)
 * If we are going to quote Webster's dictionary, at least look at its definition for the Milky Way. It clearly uses "the". Not to mention, the rest of our article uses "the". Even if we acknowledge that there may be other "solar systems", you have to realize that it is not necessary to keep "our". Also Webster's dictionary is not an astronomy dictionary, since it lists everyday (and even incorrect or nonexistent) words. If we take a look at an actual astronomy dictionary, you would see it has no such mention of other "solar systems": Oxford Dictionary of Astronomy, The Facts on File Dictionary of Astronomy. --AYFKM (talk) 20:25, 6 February 2016 (UTC)
 * Wikipedia is not a dictionary and you are probably not a lexicologist or a lexicographer..... so we do not divine word usage via how we see it used.... not our job. We go by clear definitions given by reliable sources, not original research/POV of how we think words are/should be used. Fountains of Bryn Mawr (talk) 21:57, 6 February 2016 (UTC)
 * What we need is consistency. Remember that even the source you provided is contradicting itself; on its Milky Way definition, it clearly says "the solar system". --AYFKM (talk) 22:51, 6 February 2016 (UTC)
 * It's been a month now. Unless anyone has any real reason to object, I'll change it to "the". -AYFKM (talk) 21:18, 7 March 2016 (UTC)

Err.... no, you should read this talk page. The discussion died, the ((Dubious)) tag was removed by an un-involved editor, no clear rational or reference was provided for a change. So there is a very real reason not to change it. Fountains of Bryn Mawr (talk) 21:50, 7 March 2016 (UTC)

Dubious tag
So it's been about a month now. Don't you think we should remove the dubious tag? First, it is polluting the lead. Second, the average reader may not understand what it means. They will think that the fact the solar system is in the Milky Way is dubious, when in fact, the tag refers to just an insignificant discussion over a pronoun. Huritisho 04:38, 6 October 2015 (UTC)
 * Agree, discussion went stale pretty fast and there has been no new comment. Fountains of Bryn Mawr (talk) 12:51, 6 October 2015 (UTC)
 * I really wish there was an edit war over that pronoun, so I could add all of you guys in wikipedia hall of lame. Huritisho 15:58, 6 October 2015 (UTC)

What's this thing with the Featured Articles
Earth and Solar System are both Featured Articles that avoid first person. Milky Way uses first person, and it is not a Featured Article. When writing non-Featured Articles, shouldn't we learn something from the Featured Articles?--Proud User (talk) 11:56, 12 October 2015 (UTC)
 * Umm, the difference between this article being a featured article and not isn't these three letters. And those two articles would remain featured articles if they were switched to "our Solar System". Featured articles are generally (though not always!) better than non-featured articles, but that certainly doesn't mean that every wording choice in any given featured article is different than similar wording choices in non-featured articles. Therefore, this argument is specious. And again, I do personally prefer "the Solar System", though I recognize that "our Solar System" is a perfectly valid writing choice that a number of editors prefer. And as mentioned above, the context for referring to the Solar System in this article is different than in the two you mention in a way that arguably makes "our" more appropriate here. —Alex (Ashill &#124; talk &#124; contribs) 15:07, 12 October 2015 (UTC)
 * Thank you, Alex. Each article is different, and sometimes the details of how the English language is used depends on context. Isambard Kingdom (talk) 18:03, 12 October 2015 (UTC)

Billion
Alice&#39;sleftfoot,esq (talk) 15:16, 21 October 2015 (UTC)10-21-15 There is a disagreement between 2 Wikipedia articles ("Milky Way" & "IC 1101" in the use of the term "billion" as there is between American & British use of the word. Wikipedia does provide scientific notation next to the term in each article which makes it clear (for those Looking for it) that the word has a different meaning in each article. This is probably a problem in many artlicles.  Does it need fixing or is the scientific notation sufficient?Alice&#39;sleftfoot,esq (talk) 15:16, 21 October 2015 (UTC)
 * Both articles use the short scale as far as I can tell (ie 1 billion = 1e9). I think that the American short scale usage has won out and the long scale (billion = 1e12) is no longer in widespread use anywhere in the English-speaking world. 16:49, 21 October 2015 (UTC)

Number of atoms
For the record, the Milky Way would contain roughly 1.5-2*10u59 atoms (using helium as a yardstick, since all active stars contain a sizable portion of helium and both stars and planets also contain some proportions of metals and the other heavier elements, though these have a minor share in proportion to hydrogen and helium). 83.251.170.27 (talk) 02:14, 25 April 2016 (UTC)

Vandalism
There's been a lot of vandalism on this page. Could it be semi-protected? I'm not an Administrator so I'm not 100% familiar with the different levels of protection. Foreignshore (talk) 18:56, 21 April 2016 (UTC)


 * Mmm, I see what you mean. Sounds like a good idea - and people who are caught vandalizing the page should be sentenced to prison for five hundred (earth) years. ;) 83.251.170.27 (talk) 00:05, 27 April 2016 (UTC)

What do sources say about the proportion of total mass that is dark matter
What do sources say about the proportion of total mass that is dark matter ? From the figures given in the infobox and Milky_Way it looks like between 90% to 98% dark matter. Worth stating ? eg to compare with dragonfly 44 ? Do any RS give a narrower range ? - Rod57 (talk) 20:09, 27 August 2016 (UTC)

Number of galaxies now estimated at 2 billion+
The end of the first paragraph states that the number of observable galaxies is estimated to be as many as 200 billion. NASA just just released a statement that recent Hubble based research puts the number as at least 2 trillion. http://www.nasa.gov/feature/goddard/2016/hubble-reveals-observable-universe-contains-10-times-more-galaxies-than-previously-thought

The last sentence of that paragraph should read:

"Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis,[24] observations by Edwin Hubble showed that the Milky Way is just one of many galaxies [25][26]. Research using the Hubble Space Telescope in 2016 estimated that there are at least 2 trillion observable galaxies." [citation #]

http://www.nasa.gov/feature/goddard/2016/hubble-reveals-observable-universe-contains-10-times-more-galaxies-than-previously-thought — Preceding unsigned comment added by Tony.Bigbee (talk • contribs)


 * ✅. Worthy of note: that is not how many galaxies the observable universe "contains", it is how many it "contained".  This is a direct quote from your source and is based upon the fact that the farther out we look, the farther into the past we see.  Most of those 2 trillion galaxies have merged to make larger galaxies like those we see more nearby, as in our local cluster.   Paine   u/ c  02:55, 18 October 2016 (UTC)

Changing "our" in lead
There as been a brief discussion at the Village Pump about the informal use of "our" Solar System in the lead. I will change the word to "the" if there is no serious objection. StarryGrandma (talk) 19:27, 14 December 2016 (UTC)
 * Abundantly discussed already. Please see archives: . Isambard Kingdom (talk) 19:50, 14 December 2016 (UTC)
 * Thanks for the links to the archive. StarryGrandma (talk) 00:01, 15 December 2016 (UTC)
 * Support. I absolutely agree. This discussion is nonsensical. There is no actual argument in that discussion for why MOS:PERSON is blatantly ignored. Using "our" is okay because everyone reading the article is from Earth? you don't see Human saying "homo sapien is the binomial name of our species". And then they touch on solar system referring to other planetary systems - which even if true, there is only one Solar System (capital S capital S). Someone actually argues that Earth's solar system doesn't make sense because "the Earth does not have a solar system, the Sun does" - absolute nonsense. You can absolutely use the possessive to shorted "the Solar System from which the Earth is from/a part of" down to just "Earth's solar system". And to top it all off, the people arguing against removing "our" are, of course, the top contributors. The entire discussion smells of WP:OWN. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 14:49, 15 December 2016 (UTC)
 * I think you are expressing a very strong opinion about something that is not actually very important. And, by the way, the top contributor is an astronomer expert on the Milky Way. Isambard Kingdom (talk) 14:55, 15 December 2016 (UTC)
 * You point to that discussion and dismiss StarryGrandma's concerns as "Abundantly discussed". I have merely demonstrated that the discussion that was had was definitely lacking in some places. And I said top contributors. One person is fine, but when you have two or three of the top 5 contributors all on the same side and all shooting down suggestions, it starts to look like a WP:TAGTEAM. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 15:05, 15 December 2016 (UTC)
 * Okay. Isambard Kingdom (talk) 15:07, 15 December 2016 (UTC)
 * k Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 15:09, 15 December 2016 (UTC)

Not to kick off another argument but again guidelines such as MOS:PERSON are being invoked without being read. First sentence ---> "Wikipedia articles must not be based on one person's opinions or experiences". "our Solar System" is everyone's experience and it is not an opinion that we all live there, therefor it is wording that does not go against the guideline and the guideline is not being "blatantly ignored". Some other very solid rational needs to be cited to even open this up again. Fountains of Bryn Mawr (talk) 16:25, 15 December 2016 (UTC)
 * Seriously, read the lede for Human, there is a reason it reads like it was written by an alien. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 17:44, 15 December 2016 (UTC)
 * Ha. Actually the FAQs on the talk page express what I'm trying to get at perfectly. Basically all readers and editors are going to be human, English-speaking, and living in the Solar System, but we shouldn't refer to these facts at all. Sure, using "our" could be thought of as some sort of idiom and therefore an exception to this, but using "the" is an indisputable alternative. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 17:59, 15 December 2016 (UTC)
 * The Human FAQ notes the point of view at some times is not universal. The POV of this article's lead sentence is, literally, universal. Maybe read the archived discussions again?...."the" is covered re: average readers don't know which solar system you are talking about. Fountains of Bryn Mawr (talk) 21:35, 15 December 2016 (UTC)
 * That isn't what those FAQs say at all. Could you elaborate at what you are trying to get at? Addressing your second point, Solar System and solar system are as different as Moon and moon, there is no ambiguity. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 07:04, 16 December 2016 (UTC)
 * Please read the first two paragraphs (66%) of the FAQ. As to Solar System ---> solar system, that is an editors construct which probably means nothing to the average reader. Again, this has already been covered. I agree with StarryGrandma at this point, "that's not how I would have written it, but it is good enough" a conclusion I drew a while ago (look up ""our Solar System" looks familiar" in the archives). Fountains of Bryn Mawr (talk) 13:47, 16 December 2016 (UTC)
 * Have you read that first 66%? Those first two paragraphs are completely unrelated to this discussion, and deal with changes in tone - this is only one instance of "our" in Milky Way, and it's the one we are discussing. Ah yes, I see this discussion now, where consensus decided that "the" should be used. I absolutely disagree with you - first person should be eliminated wherever possible. And it is certainly possible here. Shall I go ahead and start the dispute resolution process? Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 19:55, 16 December 2016 (UTC)
 * If you want to link an FAQ and then pick and chose what you think proves your point that's fine. You linked a discussion that ended in keeping "our". WP:DR would probably be an argument for arguments sake since I don't see anything that would overturn status-quo ante, but knock your self out. Fountains of Bryn Mawr (talk) 01:08, 17 December 2016 (UTC)
 * Read it! Please read it! It talks about switching back and forth between first and third-person and how unnatural that would be - that doesn't apply here because it's one instance of "our". And please try to see the difference between consensus (almost everyone in that discussion agreed with "the" with good arguments given) and what actually happened (which seemed to have occurred because discussion died). Addressing dispute resolution, I think this article is just an example of a larger problem (see this page I whipped up yesterday) so I don't think of this as an argument-for-argument's-sake. Anyway, I've started by linking this discussion at the Third opinion page, please check the description I wrote for neutrality. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 08:39, 17 December 2016 (UTC)
 * Unfortunately, third opinion is only for disagreements between two contributors, this discussion already has four participants. There are other legs of dispute resolution, i.e. Dispute resolution requests (requests for comment would be the most applicable in this case), that may be able to help if desired. Best Regards, — Godsy (TALK CONT ) 11:13, 17 December 2016 (UTC)
 * Alright I'll do exactly that. New section below. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1]

I am sorry that this turned up on the Dashboard and that I saw it there. I spent the early part of my life living in ordinary places where the Milky Way arched overhead. But that was ages ago and few places are dark enough any more. I am just back from a trip to a usually dark sky place, but not only was it cloudy but it absolutely stormed. I do not care whether the lead says "our" or "the". It is my Milky Way and I miss it! Wikipedia is many encyclopedias in one built by editors with a wide variety of backgrounds and personalities. Everyone has a different way of doing things. Consensus is hard enough without having to redo it constantly. We need to be able to say "that's not how I would have written it, but it is good enough". StarryGrandma (talk) 00:45, 16 December 2016 (UTC)
 * Every article certainly brings its own unique issues! Isambard Kingdom (talk) 21:24, 16 December 2016 (UTC)

Second sentence
The second sentence of the lead reads:


 * "Its name "milky" is derived from its appearance as a dim glowing band arching across the night sky whose individual stars cannot be distinguished by the naked eye."

I suggest that this be changed to something like:


 * "The descriptive "milky" is derived from the appearance from Earth of the galaxy -- a band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye."

Thoughts? Isambard Kingdom (talk) 18:03, 20 December 2016 (UTC)


 * Sure, its name isn't 'milky', so it seems like a small but real improvement. Maybe "The descriptive term 'milky' is..."  SemanticMantis (talk) 18:53, 23 December 2016 (UTC)

✅ Thank you, Isambard Kingdom (talk) 20:08, 23 December 2016 (UTC)

Number of times the Sun oscillates per orbit
In the section "Sun's location and neighborhood", the statement "In addition, the Sun oscillates up and down relative to the Galactic plane approximately 2.7 times per orbit" is tagged as needing a citation. I found this source (from Sun), which states "The Sun's orbit is somewhat elliptical, and passes through the galactic plane about 2.7 times per orbit". Is passing through the galactic plane 2.7 times the same as oscillating up and down 2.7 times, or does one oscillation mean passing through the galactic plane two times? Gulumeemee (talk) 04:44, 27 January 2017 (UTC)
 * I think it would be better to use the sentence that you have found, especially as you have a reference for it. The concepts up and down in space are relative so saying passing through the plane is better in my opinion. Polyamorph (talk) 18:20, 27 January 2017 (UTC)
 * I changed the sentence to use passes through and added the reference. Gulumeemee (talk) 00:05, 28 January 2017 (UTC)
 * Great! Polyamorph (talk) 01:48, 28 January 2017 (UTC)

Request for comment
Which of the following should be the first sentence of this article (with the first one being status quo)? Brightgalrs (/braɪtˈɡæl.ərˌɛs/)[1] 10:18, 18 December 2016 (UTC)
 * The Milky Way is the galaxy that contains our Solar System.
 * The Milky Way is the galaxy that contains the Solar System.

Our is fine. We have had abundant discussion on this already; see above and see archive for this article:. More generally, there are many more important issues at Wikipedia than this tiny one. Isambard Kingdom (talk) 14:00, 18 December 2016 (UTC)
 * Could you please summarize the main arguments? (Hypocrisy acknowledged, my arguments summarized below) Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 19:47, 18 December 2016 (UTC)
 * No, I'm too busy. You can read the previous discussion. Thanks. Isambard Kingdom (talk) 20:23, 18 December 2016 (UTC)
 * Perhaps you should not have posted in this discussion at all if you unwilling to discuss? Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 20:29, 18 December 2016 (UTC)
 * Please note Isambard Kingdom is referring to comments already made in previous discussions, which are plentiful, on this page and as such I think they are entitled to not spend their time repeating them.Polyamorph (talk) 18:22, 19 December 2016 (UTC)

Our per Isambard Kingdom. Consensus was arrived at by many editors of more than one discussion. Fountains of Bryn Mawr (talk) 14:31, 18 December 2016 (UTC)
 * Excellent. If it's been argued before, then my arguments below should be easy for you to tear apart. With that said, I contest that consensus has been reached at all. Plenty of ambiguous discussions with good arguments for "the" though. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 20:54, 18 December 2016 (UTC)

Either the or our would be acceptable to me. However, I have problems with the use of the term Milky Way to refer to the whole Galaxy. My view is that the article should be called The Galaxy or, possibly, Milky Way Galaxy. So I would prefer the first sentence would reflect this. To me, the term Milky Way refers to the band of light in the sky, and consequently to the Galactic disk, bulge and bar, but not the entire Galaxy. It is the entire Galaxy which is the subject of this article. including the stellar halo, globular clusters, gaseous halo and dark matter halo. TowardsTheLight (talk) 15:03, 18 December 2016 (UTC)
 * As might be expected, this has also been abundantly discussed, though quite some time ago:, . Isambard Kingdom (talk) 15:47, 18 December 2016 (UTC)
 * As a way of background - the distinction between Milky Way Galaxy and the "Milky Way" was in a cleanup (I think I did) to reflect "One article - two things" and referenced to a college level text. But it was more recently changed without comment and what is there now no longer reflects the citation at the end of the sentence (fyi - same cite, newer text). It should probably be put back. Fountains of Bryn Mawr (talk) 21:22, 18 December 2016 (UTC)
 * I put a cite to that book in. Isambard Kingdom (talk) 21:45, 18 December 2016 (UTC)

The for a few reasons. The for basically the reasons that Brightgalrs indicates. In particular an encyclopedia should be written without explicitly assuming anything about the author or the reader; the use of "our" is jarring for this reason. CapitalSasha ~ talk 16:48, 19 December 2016 (UTC)
 * MOS:PERSON
 * The spirit of this policy is avoid first person at all costs as unencyclopedic.
 * MOS:SELFREF
 * The text of this policy says nothing about first-person pronouns. However, the spirit of what it does say is in-line with avoiding any references to "us humans". Every time there is an "our" in reference to something universal, you are referencing that both the author and reader are both human/living on Earth/whatever. This line of reasoning (among other things) is used in the FAQ's in Talk:Human which explain the lack of first-person pronouns in that article.
 * Precedent set by other articles
 * Human - as stated above, this article never refers to the fact that both author and reader is human.
 * Sun - "The Sun is the star at the center of the Solar System.", completely comparable.
 * Moon - "It is the fifth-largest natural satellite in the Solar System,..."
 * Earth - "the Solar System", admittedly does use "...shifts in our view of the planet."
 * About the perceived triviality of this discussion:
 * MOS:PERSON doesn't explicitly say "our" is wrong. I am relying on perceived spirit of the policy. I think it could be clarified if consensus is reached here.
 * This would give a go ahead to enforce MOS:PERSON in many instances, including references to human anatomy, psychology, and evolution (see this list to get an idea) Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 19:47, 18 December 2016 (UTC)
 * Actually, we do assume a great deal about the reader re: MOS:JARGON, WP:TECHNICAL/WP:EXPLAINLEAD/Write one level down, WP:AUDIENCE. Fountains of Bryn Mawr (talk) 17:44, 19 December 2016 (UTC)
 * Good points. The problem with your line of reasoning there it's a binary choice: either the reader is an expert in the field or they are not. Is it possible to write an article that perfectly caters to both of these? It is not. Or maybe a better answer is it is possible, but it takes two articles (Introduction to quantum mechanics vs Quantum mechanics). In Milky Way it is possible to cater to all readers regardless of which solar system they are from by using "the". As comical as that sounds, it explains the difference between the two audience assumptions. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 19:24, 19 December 2016 (UTC)
 * Note the word "explicitly" in my original response -- sure we assume certain things about what the reader is able to comprehend, but we don't tell them they are or are not an expert! CapitalSasha ~ talk 20:45, 19 December 2016 (UTC)

The Wikipedia needs to preserve it's policy of being entirely neutral and not assuming anything of the reader. Using the word our ruins that purpose, it makes the very first sentence of the article sound unencyclopedic and more of a story. If need be, instead of saying our solar system, it should be specified what our solar system is. Even though it is quite evident that most people who will be reading this article indeed like in this solar system, it is not up to us to assume that, and it does not make it okay to use such phrasing. -- Nik ol ai Ho ☎️ 03:52, 20 December 2016 (UTC)

The per User:Brightgalrs. ∞ Target360YT ∞ ( talk · contribs ) 09:43, 20 December 2016 (UTC)

Our or The equally valid. "Our Solar System" is a term in very common usage, if you read articles on nasa webpages they often refer to "Our Solar System". Our article Solar System uses The. However, this begs the question of which one, given that there are billions of solar systems in the Milky Way alone. I suggest keep the status quo and stop discussing this very minor detail ad nauseum. Polyamorph (talk) 17:21, 20 December 2016 (UTC)
 * There is no doubt that "our" is common, but a NASA webpage is not an encyclopedia. I'm glad you brought up the ambiguity point. (I'll leave the question of "planetary system" meaning the same thing "solar system" aside) There is no ambiguity at all. First, you will never find a generic planetary system referred to as "the Solar System", just as Io will never be referred to as a Moon. Second, Solar System is wikilinked to the appropriate article, further eliminating any ambiguity. And please read my comments above about the perceived triviality of this argument, either way "it's trivial" isn't an argument at all. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 12:07, 21 December 2016 (UTC)
 * My reference to the NASA webpages, the world's leading authority on space science, was to show how commonly used the term is. Io most certainly is referred to as a moon. You're expending a large amount of effort over the use of one word, in my opinion that could be better spent on something else! Polyamorph (talk) 12:58, 21 December 2016 (UTC)
 * Right, no one is questioning NASA's authority, but their websites are still not encyclopedias. To clear up the Io point: Io will never be referred to as a "Moon". "moon" yes, "Moon" no. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 17:46, 21 December 2016 (UTC)
 * I think more to the point is that Io would never be referred to as the moon. CapitalSasha ~ talk 05:09, 22 December 2016 (UTC)
 * Europa has "...orbital and rotational energy are dissipated as heat in the core of the moon, the internal ocean, and the ice crust.". That's the type of reference I was referring to. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 13:15, 22 December 2016 (UTC)

The. The use of "our" implies the existence of other solar systems from which this one needs to be distinguished. But the article solar system is entirely about a single system, uses "the" throughout, and includes nothing to suggest that the term "solar system" is applied to other systems. Maproom (talk) 07:32, 22 December 2016 (UTC)
 * comment - it should be noted Wikipedia is not an unacceptable source - WP:USERGENERATED. Acceptable sources on this do note the term "solar system" is applied to other systems .Fountains of Bryn Mawr (talk) 14:20, 22 December 2016 (UTC)


 * Comment Apart from any question of repetitiveness, this is storm-in-teacup stuff. Wasting time on trivialities is IMO as pernicious as deliberate vandalism, but if anyone feels that precision is vital even in incidental wording that readers could understand without explanation (which I could sympathise with) then at least get the subjects clear. The item contains four concepts to be distinguished: Milky way (what we see as a naked-eye manifestation of the galaxy in which we find ourselves, for practical purposes the only naked-eye galaxy relevant to this subject), galaxy (of which there are many, should anyone wish to distinguish any particular one), solar system, of which there are more by now documented than most of us have been keeping count of, and classes of observers, of which humanity is the only one immediately relevant (citation needed for any rival claimants to the title of "we" in this matter). So: the use of "we" or "our" is fine, just as we do not quibble about speaking about "my father" even though he generally is not anyone's chattel. It might help to consider the way Americans speak of "our country" or even "my country", even addressing Chinese or Brits. "The" is less specific and accordingly more chauvinistic, though it does little harm, even in failing to distinguish which solar system we mean among trillions and trillions, or alternatively suggesting that it is so superior that no other solar system deserves consideration. Most of our readers will be able to work out its identity from Solar system, Star system and Planetary system. Similarly, "our galaxy" is unambiguous, whereas "the galaxy" is either ambiguous or overweening. Milky way actually is not the whole galaxy, but who is counting? IMO the current wording could stay, but if enough people insist, we could say something like "The Milky Way is part of the galaxy that includes our solar system; specifically it is that part that is visible to the naked eye..." (except if you make allowance for the seeing in cities and submarines of course, but please, please...!) JonRichfield (talk) 15:26, 22 December 2016 (UTC)
 * You seem to have obscured the main point being made here - that first personal pronouns shouldn't be used even for human "universals". Your examples (addressing the use of "our" in "our Solar System") would never be written in an encyclopedia, so I don't think they really hold. We have WP:PERSON that eliminates these personal-view types of things. Also, I have no opinion on if "Milky Way" refers to the view from the Earth of the galaxy that holds the Earth or if it actually refers to that galaxy itself. Though I will remind everyone that this discussion was started with "the" vs "our" in mind. But if it's grown to include "Milky Way" vs "Milky Way Galaxy", well that's fine too I guess. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 21:17, 22 December 2016 (UTC)
 * I think you mean MOS:PERSON, not WP:PERSON which has no relevance to this matter.Polyamorph (talk) 18:22, 4 January 2017 (UTC)

Our because it forms a frame of reference. Although I agree with the The arguments above when it comes to wikipedia style, I believe too many people are now too savvy in concerns to the universe, that a majority of the population is now aware that there are other worlds and solar systems being investigated by science, and that there is a substantial risk of readers wondering, "What solar system are they talking about?". Our Solar System immediately grounds the reader into knowing that the article is talking about where we live. The only other way I see to do this is to include a reference to the Earth itself, such as The Milky Way is the galaxy that contains the Solar System containing the Earth StarHOG (talk) 17:26, 23 December 2016 (UTC)
 * I don't think it's worth breaking MOS just for the reasons you list. With that said, I have no problem with something like "The Milky Way is the galaxy that contains Earth's solar system". As you can see, I don't think "Solar System" would be capitalized there. And I feel like this will inflame arguments about planetary system vs solar system. But it avoids first person, has your "frame of reference", and takes care of any perceived ambiguity (I still think Solar System is perfectly fine...). Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 21:10, 23 December 2016 (UTC)
 * And by adding Earth you instantly solve this entire argument. You kill two birds with one planet.... StarHOG (talk) 18:40, 26 December 2016 (UTC)

Our. MOS:PERSON has two exceptions to not using first person pronouns: context which refer to the world as a whole and in scientific context. Since this article qualifies on both counts, it doesn't seem MOS:PERSON should be the basis for changing it. I'm not sure how MOS:SELFREF applies at all since it is about not including references to Wikipedia in articles. How is this a reference to Wikipedia? I think appeals to the spirit of policies is unconvincing. If an editor feels a policy should prohibit something, it seems the editor should first get that policy changed to reflect that prohibition and then use that changed policy as the basis to change other articles. In this case, it seems the basis for wanting to change this article is a desire that the referenced policies prohibited the style in the article. Klaun (talk) 21:33, 27 December 2016 (UTC)
 * Read MOS:PERSON a little closer, it mentions two idiomatic uses: 1) referencing modern society in historical articles, neither are applicable here and 2) the author's we for shortening proofs, explanations, step-by-step stuff, again not applicable; also the MOS says it should be avoided for passive voice. I thought I hedged my use of WP:SELF enough, but alright, here it goes. You are right about WP:SELF in that it is written warning editors against references to what they are reading (an article), how they are reading it (a web browser), and the website they are browsing (Wikipedia). But surely you can see how that can be extended to other things, like the language they are reading in (English), the species they are (Human), and then the place they are reading it from (Solar system, Milky Way). As for spirit vs letter of the law, these policies don't claim completeness in the examples they provide, which allows room for this discussion to clarify them. And specifying policy is exactly what we are doing here. Consensus built on this talk page and consensus built on a policy talk page are equivalent. Brightgalrs  (/braɪtˈɡæl.ərˌɛs/)[1] 19:16, 1 January 2017 (UTC)
 * No, sorry but WP:SELF is completely irrelevant in this case. Polyamorph (talk) 13:00, 4 January 2017 (UTC)
 * A policy such as WP:SELF cannot not be extrapolated to address this issue, WP:SELF refers only to self reference of wikipedia content. It's not at all in the spirit of the policy, it's completely irrelevant to it. Also the two uses that you cite from MOS:PERSON are examples only and not the sole limit of their possible use. The policy states that although "we", "us", and "our" should be avoided, they are not strictly prohibited. In any case, even if it the use of "our" was explicitly prohibited, which it isn't, the MoS is not law anyway and can be ignored if necessary. Polyamorph (talk) 14:46, 4 January 2017 (UTC)

The. It matches the style in the Solar System's article and (in my opinion) reads better. Andrew327 15:57, 29 December 2016 (UTC)

The, but in The Milky Way is the galaxy that contains the Earth (or similar). Frankly, storm in the teacup and all that, but if the problem is that "Solar System" is ambiguous even with a wikilink, that sounds like the best option. "Our" does seem somewhat unencyclopedic, and should be avoided if not needed. (bot-summoned) Tigraan Click here to contact me 16:04, 31 December 2016 (UTC)

Our. Avoiding WP:BIAS is good, but wikipedia is so far only used on Earth and even with the prospect of interplanetary travel its readers won't leave our Solar system soon. The term Solar system is often used to refer to a Star system (even by NASA), so without our the reader might not understand which solar (star) system the description refers to. &#8220;WarKosign&#8221; 08:00, 3 January 2017 (UTC)
 * I do not think the problem is one of WP:BIAS - none has argued AFAICT that "our" is an "earthist" term discriminating against martians or something similar. The argument is WP:TONE, in particular articles should generally not be written from a first- or second-person perspective - even though the disambiguation issue is a plausible reason to use "our". Tigraan Click here to contact me 17:27, 4 January 2017 (UTC)
 * Actually it would be discrimination against Alpha-centaurians. As an alternative to our, how about something like "The Milky Way is the galaxy that contains the Solar System (which contains Earth)" ? &#8220;WarKosign&#8221; 15:21, 8 January 2017 (UTC)


 * Comment since this RfC has now run its course, I have requested closure of the RfC by an uninvolved editor here. Best Polyamorph (talk) 10:04, 27 January 2017 (UTC)
 * Our – This choice of pronoun immediately establishes that our solar system is not the only one in existence, which is a very fitting way of introducing the concept of a galaxy, as a bunch of solar systems lumped together by gravity. If we change to "the Solar System", it begs the question "which one?", and Grandiose Caps Don't Make Our Solar System Any More Notable Than Any Other In The Galaxy, Really. — JFG talk 23:22, 28 January 2017 (UTC)
 * Comment on Closure - An editor closed this discussion but I specifically asked for the consensus to be assessed here and as such have reverted their closure until another editor is able to close it properly. Thanks. Polyamorph (talk) 10:00, 8 February 2017 (UTC)

Semi-protected edit request on 28 February 2017
Section Contents: change "The nearest such planet may be 12 light-years away, according to scientists." to:

"The nearest such planet may be 4.2 light-years away, according to a 2016 study." 213.33.68.50 (talk) 12:45, 28 February 2017 (UTC)


 * ✅ and thanks! Polyamorph (talk) 12:56, 28 February 2017 (UTC)

Semi-protected edit request on 17 April 2017
Generation of spiral galaxy-like structures in the laboratory

Spiral galaxy-like structures can be generated in the laboratory. When potassium sulfate is heated in water and subjected to swirling in a beaker, the crystals form a multi-arm spiral structure when allowed to settle https://link.springer.com/article/10.1134/S1990793117010328. The phenomenon could be used to study galaxy formation. Abetom (talk) 19:32, 17 April 2017 (UTC)


 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. —MRD2014 📞 contribs 02:18, 18 April 2017 (UTC)

Semi-protected edit request on 18 April 2017
When potassium sulfate is heated in water and subjected to swirling in a beaker, the crystals form a multi-arm spiral structure when allowed to settle Abetom (talk) 23:02, 18 April 2017 (UTC)


 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. Please make sure to clarify what you want to change. —MRD2014 📞 contribs 23:11, 18 April 2017 (UTC)


 * I disagree with the proposed edit. I do not see the relevance of crystal growth in a beaker to the formation of spiral arms in the Galaxy. The physical processes will be very different, and there are many research papers in research journals about the growth of spiral structure in galaxies based on a detailed consideration of the physical processes operating in galaxies. Crystal growth is not relevant here.TowardsTheLight (talk) 10:40, 19 April 2017 (UTC)

It is not known how spiral galaxies including Milky Way are formed. Potassium sulfate does not form spiral shaped crystals, rather the spiral structures are formed only during cessation of a swirling beaker. Kindly start a section on: Generation of spiral galaxy like structures in the laboratory, towards the end of the section. The section will motivate the community on how multi arm galaxies could be generated in the laboratory. This study spans the new field of laboratory astrophysics. — Preceding unsigned comment added by Abetom (talk • contribs) 20:38, 19 April 2017 (UTC)
 * , please sign your comments by putting ~ at the end. Wikipedia isn't the place to publish new ideas. Your reference is a newly published paper. The paper is published in a chemistry journal and the abstract of the paper does not mention galaxies. If this becomes a topic of research within laboratory astrophysics with multiple groups doing research, then it might merit a section in Spiral galaxies. StarryGrandma (talk) 22:23, 19 April 2017 (UTC)

Much ado about Planets
WP:ER I came here to obtain information about the structure of the Milky Way, but to my surprise found that this page is to a large extent preoccupied with the existence, and even more the amount, of planets in the Milky Way. There are currently 31 occurrences of words occurrences of words containing "planet" in the article. Furthermore the article contains the confusing There are probably at least 100 billion planets in the Milky Way vs later and at least 100 billion planets (someone may want to make an overhaul of his usage of probabilistic terminology). I don't mind planets in the least. In fact, I'm very grateful to be living on one. I'd also be happy to read about them, for instance in an article named The number of planets in the Milky Way or similar. However, coming to what is supposed to be an article about a galaxy, I'd rather prefer said article to be a bit more focused on stars than on planets. 212.85.89.146 (talk) 07:34, 20 April 2017 (UTC)

Barred Spiral Galaxy
My recollection is that the Milky Way Galaxy was determined to be a barred spiral galaxy in the relatively recent past (maybe even in the current century), but there is nothing about this either in this article or in the article on barred spiral galaxies. I think something should be included about the time period when this was discovered. I putzed around a while in the notes trying to find a date or a source, but I couldn't locate one right away. Shocking Blue (talk) 11:05, 20 June 2017 (UTC)

Perspective bias
Should not the lede the article correctly be worded as: "The Milky Way is the galaxy that contains  Earth's  Solar System." rather than " our  Solar System."? The use of  presumes the reader lives in said Solar System, which in in conflict with WP:BIAS. → Michael J Ⓣ Ⓒ Ⓜ 22:29, 3 July 2017 (UTC)
 * ? I think we can safely assume that. The situation may change but by that time Wikipedia and all the computers its hosted on will probably be a compressed layer of trash 500 feet down and two centimeters thick. Fountains of Bryn Mawr (talk) 01:49, 4 July 2017 (UTC)

Number of stars inconsistency
The second paragraph of the Milky Way page states that "the Milky Way is estimated to contain 100–400 billion stars", the same size range is repeated in the page's Infobox, while the first sentence of the 'Contents' section says "the Milky Way contains between 200 and 400 billion stars" - each are supported by online references. I would like to suggest that Milky Way page editors establish the latest scientific estimates and make this aspect of the article consistent throughout.

Mattstan (talk) 10:54, 9 November 2017 (UTC)

mass Milky Way vs. Andromeda

 * roughly equaling the mass of Andromeda Galaxy at 7 within 160000 ly of its center. In 2010, a measurement of the radial velocity of halo stars found that the mass enclosed within 80 kiloparsecs is 7 . According to a study published in 2014, the mass of the entire Milky Way is estimated to be 8.5, which is about half the mass of the Andromeda Galaxy.

First the mass of Andromeda is about 7*10^11 solar masses, then it's about 17*10^11. If this is switching between talking about the mass of all stars, and talking about all mass in the galaxy's volume, this should be made clear. If not, one of those comparisons to the mass of Andromeda is wrong. Jmichael ll (talk) 02:45, 12 November 2017 (UTC)

Number of stars in the Milky Way
In the first paragraph, it is stated that there are 100-200 billion stars, but later in the article, 200-400 billion. — Preceding unsigned comment added by 8.21.73.166 (talk) 13:58, 26 December 2017 (UTC)

Contents section
The contents section looks like people just kept on adding updates to new information instead of restructuring the section to be uniform. You can see this with the differing numbers of planets & stars. JanderVK (talk) 18:00, 6 April 2018 (UTC)

Semi-protected edit request on 17 April 2018
93.190.152.161 (talk) 10:55, 17 April 2018 (UTC)
 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Nici  Vampire  Heart  11:15, 17 April 2018 (UTC)

So many errors in the article
The latest research on Milky Way galaxy includes data on its Mass, approximate size and number of stars. Size = 175 - 225 000 light years, Mass = 720 - 850 Solar masses, depending which variable used, almost identical to Andromeda Galaxy. Number of stars = 550 billion stars, at least, could be up to a trillion stars. Number of planets = so far we discovered over 3700 planets confirmed in 2700 solar systems observed, most of the planets observed were large therefore easily detectable, and in angle easier for us to observe the observed planets. Number of planets could be way above 5 trillion, number of Earth Like planets - in excess of 550 billion, number of habitable planets, one's imagination. Article needs major update, it looks like it was written in the 1950s. — Preceding unsigned comment added by 95.151.44.239 (talk) 22:47, 16 May 2018‎


 * Not clear. This is an active research topic.  But, e.g.. a quick search of APOD (apod.nasa.gov), for articles published after 2015, the date of our supporting article, shows that the APOD astronomers still use the 100,000-LY size.  E.g.:


 * M101 (https://apod.nasa.gov/apod/ap180504.html), "170,000 light-years across, ...almost twice the size of our own Milky Way"
 * NGC 1309 (https://apod.nasa.gov/apod/ap160714.html), "30,000 light-years, making it about one third the size of our larger Milky Way".
 * NGC 4647 (https://apod.nasa.gov/apod/ap160128.html), "90,000 light-years, about the size of our own Milky Way".
 * NGC 6744 (https://apod.nasa.gov/apod/ap170526.html), "175,000 light-years across, larger than our own Milky Way."


 * This suggests that the astronomical community does not (yet?) fully accept the upper end of the range in the WP article's popular-science 2015 citation, much less your 175-225 KLY range.


 * I suggest using the 100 KLY size until there is evidence of a consensus for something other than 100 KLY -- at least a consensus of the range of values, if not of a single value. Jmacwiki (talk) 18:30, 19 May 2018 (UTC)

Velocity
(Great article, thanks to everyone involved.) Herbmuell (talk) 18:58, 23 June 2018 (UTC)
 * Two cosmological reference frames are cited: the Hubble flow = the motion of astronomical objects due solely to the expansion of the universe (citation from Hubble's law), and the cosmic microwave background (CMB). How can there be a difference between the two? The two reference frames should be identical by definition. (To be more specific, the reference frame where the CMB has no dipole component in temperature.)
 * I would have expected that the CMB is the one reliable way to measure our proper motion. The first figure 630 km/s + direction seems to have been obtained by measuring the motion of many "neighbouring" galaxies relative to us. While it's good to look at this, this seems to me an inferior method to measure our proper motion. Who came up with 630 km/s + direction (vaguely described as Great Attractor)? What's the reference? "Astronomers believe..." Ouch!
 * Have both figures and directions been corrected for the rotation of our solar system around the centre of the Milky Way?

M32p
ok a sister galaxy to milky way, eaten by andromeda. thats a very big thing, that really existed, and is highly notable. i know we dont know much about it, but i think it deserves an article.(mercurywoodrose)50.193.19.66 (talk) 17:29, 23 July 2018 (UTC)

Mass inconsistencies
The range of estimates of total mass is fairly large. The article quotes some ranges, though it seems to give equal weight to older and more recent estimates. However, the bigger problem is that it quotes different ranges in different places. This needs a careful edit, even if it just mentions the uncertainties in each place.

This will also affect the Andromeda Galaxy article because of MW comparisons quoted there. Jmacwiki (talk) 01:09, 6 August 2018 (UTC)

New diameter, article needs an update
100 to 160 kly needs to be updated through the article, whoever has time for it. — Preceding unsigned comment added by 62.57.247.119 (talk) 20:38, 27 July 2018 (UTC)


 * I can't tell if there is any consensus in the astrophysical community about this increased diameter. I don't have access to ref. #3 (A&A journal paper); but note that the cited ref. #4 (Space.com) is a popular-science article that quotes a knowledgeable third party (Heidi Newberg) who hedges on this very point.


 * I assume, but have not discovered, that the community is pondering how few stars constitute a galactic presence, and how gradual a thinning constitutes an end to the disk.


 * At the moment, Netdragon's assertion that the 150K+ LY diameter is firm seems aggressive. I won't revert now, but as recently as a few months ago, NASA astronomers were still saying, explicitly or implicitly,  that the MW's diameter is 100K LY or even a little less (https://apod.nasa.gov/apod/ap170712.html, https://apod.nasa.gov/apod/ap171109.html, https://apod.nasa.gov/apod/ap180504.html, https://apod.nasa.gov/apod/ap180525.html).  Jmacwiki (talk) 05:38, 14 August 2018 (UTC)

thickness of disc is inconsistent in article
Hi,

The outliner says that the thin stellar disk is roughky 2ky light years thick. The first sentence is in chapter "Size and mass" is stating "The Milky Way is the second-largest galaxy in the Local Group, with its stellar disk approximately 100,000 ly (30 kpc) in diameter and, on average, approximately 1,000 ly (0.3 kpc) thick."

Both are linking to the same two sources:

https://web.archive.org/web/20130924002929/http://www.universetoday.com/75691/how-big-is-the-milky-way/ which is stating "estimated 1000ly" for the disk

https://link.springer.com/article/10.1007%2Fs00159-013-0061-8

Which is saying: "In a casual, luminosity or mass-weighted average, the Disk can be characterized as a highly flattened structure with an (exponential) radial scale length of 2.5–3 kpc and scale height of ≃0.3 kpc (e.g., Kent et al. 1991; López-Corredoira et al. 2002; McMillan 2011), which is kinematically cold in the sense that the characteristic stellar velocity dispersions near the Sun of σ z ≃σ ϕ ≃σ R /1.5≃25 km s−1 are far less than v circ≃220 km s−1." 0.3 kpc is roughly equal to 1000ly.

I am not changing the 2ky because I don't completely understand what the radial scale length is, but it is clearly separated from the height/thickness.

Best regards,

Andy — Preceding unsigned comment added by 2A02:8084:90E1:4280:98C1:B1F6:DD66:477B (talk) 16:28, 18 November 2018 (UTC)

Semi-protected edit request on 20 November 2018
Hi,

The thickness of the disc is inconsistent in article

The outliner says that the thin stellar disk is roughky 2ky light years thick. The first sentence is in chapter "Size and mass" is stating "The Milky Way is the second-largest galaxy in the Local Group, with its stellar disk approximately 100,000 ly (30 kpc) in diameter and, on average, approximately 1,000 ly (0.3 kpc) thick."

Both are linking to the same two sources:

https://web.archive.org/web/20130924002929/http://www.universetoday.com/75691/how-big-is-the-milky-way/ which is stating "estimated 1000ly" for the disk

https://link.springer.com/article/10.1007%2Fs00159-013-0061-8

Which is saying: "In a casual, luminosity or mass-weighted average, the Disk can be characterized as a highly flattened structure with an (exponential) radial scale length of 2.5–3 kpc and scale height of ≃0.3 kpc (e.g., Kent et al. 1991; López-Corredoira et al. 2002; McMillan 2011), which is kinematically cold in the sense that the characteristic stellar velocity dispersions near the Sun of σ z ≃σ ϕ ≃σ R /1.5≃25 km s−1 are far less than v circ≃220 km s−1." 0.3 kpc is roughly equal to 1000ly.

While I don't completely understand what the radial scale length is, it is clearly separated from the height/thickness.

Best regards,

Andy 2A02:8084:90E1:4280:E3:FB2:B4A1:47E5 (talk) 21:28, 20 November 2018 (UTC)
 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate.  Spintendo   02:14, 22 November 2018 (UTC)

Introduction
Wouldn’t it be more encyclopaedic to say "The Milky Way is a galaxy..." instead of even mentioning our solar system, as in the grand scheme, it is not important.  IWI  ( chat ) 09:55, 10 December 2018 (UTC)


 * Answer: No, since over 99% of the readers will be located in that single, unimportant system.Magyar25 (talk) 21:27, 15 December 2018 (UTC)


 * No, per:MOS:LEADSENTENCE, clearly part of the definition. Fountains of Bryn Mawr (talk) 21:56, 15 December 2018 (UTC)
 * Yes but we should have no POV; the use of "our" is a POV. This is a record of knowledge, don't you think its a little self-centred of us to relate a whole galaxy to one system within it, when there are billions of them?  IWI  ( chat ) 21:46, 21 December 2018 (UTC)
 * POV issues only apply when everyone may not share that POV. Not the case here, we all share that POV, no exceptions. Also see RFC. Fountains of Bryn Mawr (talk) 15:47, 22 December 2018 (UTC)

I understand that but there is only one Solar System. Would we say "Europe is a continent on our Earth"? No because, like the solar system there is only one. Also consensus was hardly reached on that RFC.  IWI  ( chat ) 15:11, 23 December 2018 (UTC)
 * There's no such policy as "no POV"; npov stands for "neutral point of view" ("all of the significant views"), not "no point of view". Rolf H Nelson (talk) 20:22, 31 December 2018 (UTC)
 * Merriam Websters doesn't agree with you and we should probably go by that. Fountains of Bryn Mawr (talk) 17:09, 23 December 2018 (UTC)
 * No. The Solar System is the system containing the Sun. It is not interchangeable with "Star System" or "Planetary system". That is fact, doesn’t matter what Merriam Webster says.  IWI  ( chat ) 19:31, 23 December 2018 (UTC)
 * Also looking at others is a good idea.  IWI  ( chat ) 19:38, 23 December 2018 (UTC)
 * You don't get to pick and chose your sources and your third dictionary hit says "the sun and the group of planets that move around it, or a similar system somewhere else in the universe". You are claiming there is a standard nomenclature but provide no proof of it. Without standard nomenclature we have to go by what the common use of the word is, what the reader understands, and common sense. There has been voluminous talk and an RFC covering this and you are not bringing up anything more than was discussed (to death) there. Fountains of Bryn Mawr (talk) 01:35, 24 December 2018 (UTC)
 * I think that it refers to colloquial usage anyway. The discussion appears to have not reached consensus and was closed prematurely. Maybe we can find an expert on this topic, someone to clear it up. The word "solar" definitely refers to the Sun. "Solar system" – literally "system of the Sun".  IWI  ( chat ) 01:46, 24 December 2018 (UTC)

We don't do our own etymology and you are still repeating what came up in the RFC and previous discussions. You can always try another RFC but it would probably not overturn status quo. Fountains of Bryn Mawr (talk) 02:16, 24 December 2018 (UTC)
 * Every astrophysicist would cringe at the idea of "several" solar systems. For example, weight and mass have different articles because they are different things, but colloquially, they are the same. But we follow the scientific route, by having separate articles; we don't state that mass and weight are the same thing just because that is what people think (if you look in dictionaries, they will be synonymous). The same logic should apply here. Have a good Christmas.  IWI  ( chat ) 22:36, 24 December 2018 (UTC)


 * "Every astrophysicist would cringe at the idea of "several" solar systems." - one of them didn't. Fountains of Bryn Mawr (talk) 03:01, 26 December 2018 (UTC)


 * Because some unnamed author on a page on the NASA website means anything. Show me an actual journal and I will leave this subject.  IWI  ( chat ) 04:19, 28 December 2018 (UTC)


 * Author would be that astrophysicist. There have been many augments based on a claim that there is a hard and fast nomenclature but they have always failed WP:BURDEN. You can fulfill the burden or exorcise the better half of WP:IDHT. Further "yes it is!!!, not it isn't!!!" is pointless and disruptive. Fountains of Bryn Mawr (talk) 16:58, 28 December 2018 (UTC)


 * Whether

At the Milky Way's heart is Sagittarius A which is the location of a Supermassive Black Hole
At the heart of the Milky Way is Sagittarius A - a supermassive black hole like those that are now generally accepted to be at the centers of most if not all spiral and elliptical galaxies. 2601:580:101:5260:20EE:8582:B1F8:E535 (talk) 14:06, 10 January 2019 (UTC)

Semi-protected edit request on 12 February 2019
Please change, "The Milky Way consists of a bar-shaped core region surrounded by a disk of gas, dust and stars" to, "The Milky Way consists of a bar-shaped core region surrounded by a warped disk of gas, dust and stars". SilverVoyage (talk) 00:49, 12 February 2019 (UTC)

✅ Multiple news outlets have reported on it. I only included one of the requested sources as well as the original paper though, as I felt five sources would be overkill. &#160; Discant  X  22:07, 22 February 2019 (UTC)

Lead sentence pronoun
The Manual of Style generally recommends against using first-person pronouns. Saying that the Milky Way is in "our" Solar System makes it come off as too personal and doesn't really fit the encyclopedic tone. Additionally, there's only one Solar System and the capitalization makes it clear that it's a proper term. We do not need to distinguish it from others, and any ambiguity is covered by the wikilink and the rest of the article.

Note by the way of comparison that the article for Solar System calls it the planetary system of the Sun (not "our planetary system"), and Sun just defines itself as part of the Solar System (not "our star"); in neither case was it needed to explicitly bring the reader into it.

I propose changing the wording to "the galaxy that contains the Solar System". Thanks. Opencooper (talk) 08:05, 5 May 2019 (UTC)
 * This is not a new issue. See the discussions at Talk:Milky Way/Archive 5 and Talk:Milky Way/Archive 5. StarryGrandma (talk) 23:19, 5 May 2019 (UTC)
 * Indeed. But both discussions are from 2016 and consensus can change. Opencooper (talk) 04:57, 6 May 2019 (UTC)

Lead sentence pronoun
The Manual of Style generally recommends against using first-person pronouns. Saying that the Milky Way is in "our" Solar System makes it come off as too personal and doesn't really fit the encyclopedic tone. Additionally, there's only one Solar System and the capitalization makes it clear that it's a proper term. We do not need to distinguish it from others, and any ambiguity is covered by the wikilink and the rest of the article.

Note by the way of comparison that the article for Solar System calls it the planetary system of the Sun (not "our planetary system"), and Sun just defines itself as part of the Solar System (not "our star"); in neither case was it needed to explicitly bring the reader into it.

I propose changing the wording to "the galaxy that contains the Solar System". Thanks. Opencooper (talk) 08:05, 5 May 2019 (UTC)
 * This is not a new issue. See the discussions at Talk:Milky Way/Archive 5 and Talk:Milky Way/Archive 5. StarryGrandma (talk) 23:19, 5 May 2019 (UTC)
 * Indeed. But both discussions are from 2016 and consensus can change. Opencooper (talk) 04:57, 6 May 2019 (UTC)

"3 GYr older than thought"??
Article states, "The discovery of [a certain star] in the Milky Way galaxy suggests that the galaxy may be at least 3 billion years older than previously thought." However, the article makes it clear that many other MW stars are of similar age. So what do we mean by "previously"? Or else, how does this star implicate the origin date (perhaps a merger of a few smaller galaxies) in a way that the other old stars do not? Jmacwiki (talk) 05:29, 8 July 2019 (UTC)

Size: what to do with observations indicating a halo diameter of ~1 Mpc
This is the current statement in the lede regarding size of the Milky Way:


 * "The Milky Way is a barred spiral galaxy with a diameter between 150,000 and 200,000 light-years (ly)."

This is a common problem in science when the best estimate is presented as definitive fact. Information presented this way conveys an often unfounded sense of confidence. Here is the statement which follows that one:


 * "It is estimated to contain 100–400 billion stars and more than 100 billion planets."

The wording presented here does a much better job in indicating that the quantification represents the current estimate. When it comes to size, the first ways that this article presents that info fails to indicate that our best current understanding could very well be mistaken. The infobox over on the right side states that the diameter is "150–200 kly (46–61 kpc)". Contrast that with the next line which presents the info that the thickness of the thin stellar disk is "≈2 kly (0.6 kpc)".

Well there are those who have analyzed the data regarding size and have arrived at a conclusion that it is significantly bigger than what is stated definitively in the lede. For example, this paper from 2014 by lead author Tetsuya Fukushima titled "The stellar halo of the Milky Way traced by bluehorizontal-branch stars in the Subaru HyperSuprime-Cam Survey" (https://arxiv.org/pdf/1904.04966.pdf) arrives at a conclusion that the halo surrounding the Milky Way has a sharp boundary at "r≃160kpc". That converts to ~522 kly, giving a diameter greater than 1 Mpc.

Two issues are apparent in how the lede presents this info:
 * - It can do a better job of communicating what the diameter is referring to (disc vs halo), and
 * - It can do a better job of conveying our confidence in what our current best observations and calculations indicate.

You do not have to be a specialist in the history of science to know that it is a story of continual progress in improvements in observations and also improvements in the theory behind our calculations. And one of the biggest aspects of errors that are made is that the best current understanding is often presented as being the definitive answer, being blind to the trajectory of improvements that led to the current state and blind to the likelihood that this trajectory might continue into the future into a range which is outside of the bounds that are currently placed. Given all of these considerations, it seems that it would be an improvement to this article, and to science at large, if we were to change that lede statement to something which reads more like this:


 * "The Milky Way is a barred spiral galaxy with a disc having a diameter estimated to be between ..."

And we could even add another statement to the lede to let the reader know that the disc is not all that there is when it comes to spiral galaxies. Something along the lines of:


 * "...and a surrounding halo that has been observed to extend out to a radius of ~522 kly."

There are researchers who specialize in this, and I think it would be excellent if someone from their community were to make these improvements to the article. Here is one exchange on this topic from the Talk archive initiated back in 2014: [https://en.wikipedia.org/wiki/Talk:Milky_Way/Archive_5#Problem_with_the_Milky_Way's_description_and_size. TalkArch5] -- Tdadamemd19 (talk) 02:12, 14 July 2019 (UTC)
 * Totally agree that this information must be included, especially the sharp border of the halo at ~522 kly is new and very interesting. JRB-Europe (talk) 02:27, 19 July 2019 (UTC)

Diameter edits
We seem to be at risk of an edit war regarding the MW's "true" diameter.

The issue is that detecting a few MW stars far beyond the rest of the MW can be considered to redefine its diameter -- or not. Although the article lists some references for the 150-200 KLY diameter as early as 2015, the 100 KLY LY diameter has been used by astronomers for a long time, even as recently as last month(!): https://apod.nasa.gov/apod/ap190606.html says "... nearly 100,000 light-years across. That's about the size of our own Milky Way Galaxy."


 * (FWIW, in many other APOD articles, differences from the MW's diameter as small as 10% are enough to induce the authors to take note of the difference with phrases like "slightly smaller". So as these authors would use the phrase, "about the same size" would not extend to 150 KLY.)

It does not help our readers to use an unconventional definition of "diameter" with no explanation for why this new value is so discrepant from so many other published values. Presumably, dynamically and gravitationally, those new stars are irrelevant -- although they may say something important about the MW's history. Jmacwiki (talk) 05:21, 25 July 2019 (UTC)
 * It's actually a few billion of stars, so not trivial. The way I saw the very recently (2018 or 2019) discovered area of the Milky Way described is as an halo, that suddenly seems to stop at 522 KLY diameter. Now that this discovery is still new, one can write that until 2019 it was thought that the diameter of the Milky Way was at x KLY, but that in 2018 or 2019 a halo was discovered, that appears to extend until 522 KLY and then suddenly stops. JRB-Europe (talk) 09:37, 26 July 2019 (UTC)

FYI - new research
https://www.bbc.co.uk/news/world-us-canada-49182184 – BBC: "Our galaxy, the Milky Way, is 'warped and twisted' and not flat as previously thought, new research shows."

I just saw this, for anyone interested in astronomy who might update the article with the right terminiology, science, etc. Unfortunately, the BBC's source is behind a paywall. — Marcus (talk) 11:45, 2 August 2019 (UTC)

I don't know how to do this correctly by wiki standards, but  https://phys.org/news/2019-08-d-milky-galaxy-cepheids.html

distance of galactic center??
The text and the data table specify the distance from Sun to SgrA* as 8.09 kpc. Measurements differ, 6 sources are mentioned (11,12,13,95,96,97) but none of these lists this particular value - so where does it come from, and should it be replaced by the most recent determination? Tom Peters (talk) 15:12, 23 October 2019 (UTC)

Capitalization
I believe that it is conventional in professional astronomy to capitalize the words "Galaxy", "Galactic", etc. when they refers to our Milky Way. When referring to other galaxies, the word should be lower case. It looks like this article uses capitalization inconsistently and should probably be corrected. DrCrisp (talk) 06:30, 4 December 2019 (UTC)


 * Yes, that's absolutely right. The words `Galaxy' and `Galactic' should be capitalised when referring to our own Galaxy (the Milky Way Galaxy). The article should do this throughout. TowardsTheLight (talk) 10:13, 4 December 2019 (UTC)


 * This is an exception covered in MOS:CELESTIALBODIES. Milky Way galaxy is a descriptive phrase, without capitalized "galaxy", and should usually be reduced to the actual name, Milky Way, because that name is not ambiguous. Extensive discussion (including this topic) here, but no clear consensus to change the MOS.


 * In the literature it is common to see "Milky Way galaxy" along with phrases like "surveys of the Galaxy" and "the Galactic plane" when refering specifically to the MW. The IAU Style Book specifically gives as examples "the Galaxy, galactic coordinatees" on p S27 and "structure of the Galaxy" on p S24. I didn't find any specific mention of Milky Way. I diasagree that that there is any "convential" or consistent usage as journals rarely enforce IAU style and numerous authors adopt their own conventions.


 * I have no strong opinion except that usage should be consistent throughout the article. I tend to agree with "Milky Way galaxy" as that seems prevalent in sources. FWIW, that is also the dictionary usage. --mikeu talk 12:39, 4 December 2019 (UTC)

New estimate of Milky Way mass?
Here's a recent (Dec-09-2019) article A robust estimate of the Milky Way mass from rotation curve data. Providing for discussion sake. I don't know enough about the science to incorporate results based on the linked article (or whether required). --Catrachos (talk) 17:16, 12 December 2019 (UTC)
 * These are all estimates; an estimate from a March paper was added earlier. According to a recent review paper the mass of the galaxy is uncertain by a factor of two, 0.5–2.0 . We should stick to giving a range, as we do in the infobox and not give one estimate priority over another. StarryGrandma (talk) 20:00, 15 December 2019 (UTC)

"Our Solar System" vs. "the Solar System" in the lede - 2017 consensus still stands
Time for the perennial discussion to resume, it appears. Archive 5's 2017 consensus discussion has not been overturned, as far as I see. Saying there is a consensus to the contrary proves nothing. I don't see the need for a full blown RfC, but let's see if a substantial number of editors feel otherwise. I urge reading the previous discussion before commenting. Cheers! Jusdafax (talk) 07:12, 29 January 2020 (UTC)
 * That is not how it works. I read the previous discussion, but it is no longer relevant. Consensus can be established in many ways; see WP:CONSENSUS.  In this case, although there was some back and forth, afaict the sentence has used "the Solar System" for some time now, thus establishing consensus through WP:SILENCE. You are doing the right thing raising this discussion here (per WP:BRD), but you should not have reverted to enforce your desired outcome, before discussing it.
 * My reasoning for "the Solar System" is as follows: There is only one Solar system, with the Sun ("Sol", in Latin) at the center of it. Other similar heavenly bodies are "star systems" or "planetary systems". Sometimes, the expression "solar system" is used, especially in lower case, as signifying other planetary systems. I think of this as inexact, but fairly common usage, especially among the uninitiated. I would be surprised if the preponderance of reliable sources would support that, but if they did, then I would withdraw my objection to it. As a starting point (but not an ending point) in trying to determine what the sources say, one could compare  with . This is suggestive, perhaps, but far from definitive proof. However, since the WP:BURDEN of proof is on those who would wish to establish a new consensus, you should try to marshall some evidence that supports your view and add it here, or run another Rfc, if you wish. Cheers, Mathglot (talk) 07:36, 29 January 2020 (UTC)


 * Again, to be brief, I disagree, and stand by what I believe to be the operative RfC and the closing statement. I suggest we await further comment. If need be, the participants in the 2017 RfC can be pinged. And it should be noted that WP:SILENCE, which is being cited as a justification for this overriding of established consensus, is not Wikipedia policy. To quote, "This page is intended to provide additional information about concepts in the page(s) it supplements. This page is not one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community." Jusdafax (talk) 07:41, 29 January 2020 (UTC)
 * I realize you disagree, or you wouldn't be here. However, simply stating "I disagree" with nothing to support it, is not an argument, it's simple WP:IJDLI. Please say why you disagree, based on Wikipedia policy and guidelines. Yes, we should await further comment, but to stay on the right side of WP:BRD and WP:EDITWAR, you should really revert your last edit. Mathglot (talk) 07:56, 29 January 2020 (UTC)
 * I missed your addition about SILENCE in the addition to your comment above, during the EC. I could just as easily have listed WP:EDITCONSENSUS instead, and that is policy. (SILENCE is merely an unvetted explanation of EDITCONSENSUS.)  A self-revert per WP:BRD would be a sign of good faith at this point. Mathglot (talk) 08:03, 29 January 2020 (UTC)

Here's some more data: view ngrams comparing "our solar system" with "the solar system" in Google books, with x-axis showing change over time since 1950. Current ration is about 4::1, with the frequency of "our solar system" practically double what it was in 1985 and gaining, but still trailing significantly. Mathglot (talk) 08:21, 29 January 2020 (UTC)


 * Comment There remains no consensus to change. Lengthy past discussions are documented in the archives. Cheers, Polyamorph (talk) 08:51, 29 January 2020 (UTC)
 * Agree with Polyamorph that there is no consensus to change, which is why it should remain "the Solar System." Noting in passing, that there is no need to revert a dummy edit as you did here, as it has no effect on the rendered page. But to the matter at hand: does anyone around here care about, you know, reliable sources, actual data, and policy? Because if not, I have other and better things to do elsewhere. You can do what you want, here; it's just not that important to me. If you care that much, that you're willing to edit war about it, someone else can take you to ANI; I'm through here. Mathglot (talk) 09:15, 29 January 2020 (UTC)
 * Apologies for mistaking your dummy edit for edit warring. Cheers, Polyamorph (talk) 09:37, 29 January 2020 (UTC)

Galactic radius
Would there be any benefit to including a mention of the fact that simulations by Deason et al. (2020) found the total Galactic radius, inclusive of dark matter cloud, to be approximately two million light-years (292 ± 61 kpc)? The citation is arXiv:2002.09497. Nonstopdrivel (talk) 03:05, 24 March 2020 (UTC)

Our Solar System?!
In the first line of the article, it mentions "our solar system," when it should say "the solar system." There's only one Sol. There's multiple stellar systems though... — Preceding unsigned comment added by 76.88.91.142 (talk) 00:20, 29 March 2020 (UTC)
 * See Talk:Milky Way/Archive 5, specifically the RfC. Fountains of Bryn Mawr (talk) 00:28, 29 March 2020 (UTC)

Mass of Andromeda (in comparison)
From the page:

"Because the orbital velocity depends on the total mass inside the orbital radius, this suggests that the Milky Way is more massive, roughly equaling the mass of Andromeda Galaxy at 7×1011 M☉ within 160,000 ly (49 kpc) of its center.[50] In 2010, a measurement of the radial velocity of halo stars found that the mass enclosed within 80 kiloparsecs is 7×1011 M☉.[51] According to a study published in 2014, the mass of the entire Milky Way is estimated to be 8.5×1011 M☉,[52] but this is only half the mass of the Andromeda Galaxy."

Is the mass of Andromeda ~7x10^11 M☉, or is the mass of Andromeda ~1.7x10^12 M☉? A sentence further seems to get us an order of magnitude further.

2warped@gmail.com 2601:407:4180:40E9:755C:7E4F:BFB6:1B6 (talk) 12:33, 7 May 2020 (UTC)

Just a question
Excluding UGC 12158, are there any other galaxies with a similar design? --StaleGuy22 (talk) 19:16, 7 May 2020 (UTC)

"Galaksi Bima Sakti" listed at Redirects for discussion
A discussion is taking place to address the redirect Galaksi Bima Sakti. The discussion will occur at Redirects for discussion/Log/2020 May 18 until a consensus is reached, and readers of this page are welcome to contribute to the discussion. TheAwesome Hwyh  13:12, 18 May 2020 (UTC)

"Updating required"
Article is based on 1960s scientific data and predispositions, latest data on size, and mass as well as number of stars totally at odds with this article. Milky Way Galaxy 170-200 000 light years across, 1.54 trillion solar mass and around half a trillion stars. Simple googling yields far accurate result in less than 30 seconds.  There's articles from Cornell, Cambridge and UCL as well as ESO/ESA and NASA on the matter. — Preceding unsigned comment added by 95.150.66.208 (talk) 00:34, 31 May 2020 (UTC)

Number of stars
Why the contradiction between the 2nd para of the lede, which gives the number of stars as "100–400 billion" (which is also repeated in the section 'Contents'), while the infobox claims "250–500 billion" (followed, without any hint of irony, by "(1–4)×10^11") — is it just a case of correcting the numbers in the infobox, or is there more to this than that? -- DoubleGrazing (talk) 09:52, 13 July 2020 (UTC)
 * My suspicion would be that this is the result of incremental changes over time that slipped in alongside other edits. I wonder if there's a review article on the subject? If I get some time later in the week I'll try and have a look for one. --  Newty   09:11, 15 July 2020 (UTC)

Infobox image
My main problem with the current infobox image is that it is a view of the of the Galactic Center instead of showing the Milky Way in its entirety. Isn't the entire galaxy what the article is supposed to be focusing on in the first place?

Therefore, I propose we could replace the infobox image with one of the following files:

--HyettsTheGamer2 (talk) 03:41, 2 August 2020 (UTC)


 * The Milky Way is two things, something you see in the sky, and the name of the galaxy we are seeing. The real image currently used (of the real thing) covers both aspects and is far better than some artist rendition. Fountains of Bryn Mawr (talk) 17:15, 2 August 2020 (UTC)

Failed verification of the claim "Astronomers believe the Milky Way is moving at approximately 630 km/s [with respect to the Hubble flow]"
I suspected that the claim was wrong, cause I know about the different motions and velocities in space. When I checked the book, "An introduction to galaxies and cosmology", page 298, I confirmed my suspicion. The book doesn't say that; it says that the velocity of the Local Group (not the Milky Way) with respect to the cosmic microwave background (not to the Hubble flow), derived from the motion of the sun, is 630 km/s (and the book is right).

Yes, the Milky Way is inside the Local Group, but the velocities are different; and yes, the Hubble flow is a reference frame similar to the CMB, but they can have a relative velocity depending on the sample of galaxies.

Grausvictor (talk) 09:51, 4 September 2020 (UTC)

Our solar system vs. the Solar System
In the first sentence it says, "The Milky Way is the galaxy that contains our Solar System..."

It is best if it said, "the Solar System" instead.

Using the term "our solar system" implies that there is more than one. Solar System is the name of our planetary system. Its named after Sol, which is our sun. Even though there are lots of planetary systems out there, there is only one that's called the Solar System. Appple 02:03, 29 September 2020 (UTC)


 * Red question icon with gradient background.svg Not done: Please supply reliable sources, otherwise this is simply your opinion. Also see please see the last RfD. Also please sign your posts. Fountains of Bryn Mawr (talk) 12:23, 29 September 2020 (UTC)


 * "Our planetary system is the only one officially called “solar system,” but astronomers have discovered more than 2,500 other stars with planets orbiting them in our galaxy." https://spaceplace.nasa.gov/other-solar-systems/en/


 * "There are many planetary systems like ours in the universe, with planets orbiting a host star. Our planetary system is named the "solar" system because our Sun is named Sol, after the Latin word for Sun, "solis," and anything related to the Sun we call "solar." " https://solarsystem.nasa.gov/solar-system/our-solar-system/overview/


 * "The generic term for a group of planets and other bodies circling a star is planetary system. Ours is called the solar system because our Sun is sometimes called Sol. Strictly speaking, then, there is only one solar system; planets orbiting other stars are in planetary systems." https://pressbooks.online.ucf.edu/astronomybc/chapter/7-1-overview-of-our-planetary-system/


 * Appple 04:38, 02 October 2020 (UTC)


 * Please read previous RfC. NASA sources always contradict themselves on this, in fact the first source you provided has the title "How Many Solar Systems Are in Our Galaxy?" and goes on to say "One day, by studying exoplanets and distant solar systems, astronomers hope to answer the intriguing question: Is there life elsewhere in our galaxy?". The English language is a changeable thing (check the dictionary) and we do not enforce usage. Fountains of Bryn Mawr (talk) 15:23, 2 October 2020 (UTC)

I did look at the previous discussion on this from four years ago.

If NASA has explicitly stated that Solar System is the name of our planetary system only, then that is probably the correct definition. I haven't found anywhere where they explicitly state that the two terms are interchangeable.

I would have to say that the people at NASA are human and make mistakes just like everybody else. And just because some of NASA's articles use the terms wrong by mistake doesn't mean that's the correct way to do it.

Appple 19:10, 02 October 2020 (UTC)


 * Well we can't WP:CHERRYPICK sources and its not our job to figure out usage, that has already been done for us. Fountains of Bryn Mawr (talk) 19:42, 2 October 2020 (UTC)


 * Actually, my Macquarie dictionary gives the derivation of "solar" as being from the Latin solaris. The assertion that it is "named for Sol" is rather tenuous, at least in the sense that it is directly named. Regards, Cinderella157 (talk) 23:26, 2 October 2020 (UTC)

Detecting Earth-mass Rogue Planet for first time - News or Not?
Seems the following edit (copied below) is News-Worthy - however - one editor reverted the edit as "WP:NOTNEWS" - Question: Is the edit sufficiently News-Worthy to add to the main Milky Way article - or Not?

[Edit added - then reverted by another editor]:

'''"In September 2020, astronomers using microlensing techniques reported the detection, for the first time, of an earth-mass rogue planet unbounded by any star, and free floating in the Milky Way galaxy." '''

Comments Welcome from other editors - in any case - Stay Safe and Healthy !! Drbogdan (talk) 15:18, 6 October 2020 (UTC)

Milky way diameter in the introduction
(opening this topic because of the initial warning: "Please do not change the lead sentence(s) without consulting the discussion page first. The lead sentence has been discussed and there is general consensus that this is the best one for now")

I think that the current version:

"The Milky Way is a barred spiral galaxy with an estimated visible diameter of 1.9 million light-years (ly), give or take 0.4 million light years.[23][24][25][26]"

does not really give useful info to the reader. The estimated visible diameter has been increased from the traditional 100kly to about 150-200 kly (as described in most of those references), and one paper estimates a mostly-dark matter halo of up to about 2Mly, based on simulations (as also said by the same paragraph a little later).

In addition, some references appear to be duplicates.

I intend to put back the 150-200 diameter estimates and mention the 1.9Mly as recent speculative developments, and also fix the duplicate sentences and references. Any objections? Alfio (talk) 09:12, 29 December 2020 (UTC)

Lede image
An editor just added this image as the lede image. It's gorgeous, but I don't think it makes sense as the lede image. It's a clever refactoring of the classic image of the Whirlpool Galaxy to match the shape of an artist's conception of the Milky Way that incorporates the best knowledge of the positions of the spiral arms where they're "known" and then extrapolates a guess where they're not known. I think that's a lot of extrapolation, and presenting it without context as the lede image is misleading. The existing image, just showing what the Milky Way looks like from Earth, is better, I think. This image could fit in the main body of the article with a caption making clear that it's an extrapolation. —Alex (Ashill &#124; talk &#124; contribs) 17:26, 5 March 2021 (UTC)
 * It is beautiful, but I agree that an "artist's concept" should not be the lead image unless there are no actual images available. Schazjmd   (talk)  17:35, 5 March 2021 (UTC)


 * Yes, I accepted this revision but I agree it not the best lede image. It would be nice to include it somewhere in this article and restore the previous lede image. Polyamorph (talk) 22:49, 6 March 2021 (UTC)

256 Kly
This user, Explorer king, is saying that the Milky Way is 256,000 light years across, and bases it on a radius of 129,000 light years. I know that radius estimate is from the Gaia observations, but is it actually the radius of the visible disk?--The Space Enthusiast (talk) 23:25, 4 May 2021 (UTC)
 * I mean, the radius is impossible to define anyway, at least in terms of one number, since there's no definitive edge to the Milky Way or any other galaxy. The size and mass section does an OK job of presenting some of the considerations, though it could use cleanup. —Alex (Ashill &#124; talk &#124; contribs) 06:43, 5 May 2021

I think we should lean with the 200 Kly estimate, as the 129,000 light year estimate is actually the radius of the area that Gaia surveyed, as when they published a 1.59 trillion solar mass estimate, they said that that was the mass within the 129,000 light year radius, not the diameter of the disk. Explorer King, shall we look at the reference?The Space Enthusiast (talk) 08:09, 5 May 2021 (UTC)

Sure I guess, but wouldn’t it also be a good idea if we can ask one of the scientists behind the document just so we can be clear.ExplorerKing (talk) 10:00, 5 May 2021

We could, but remember that 256,000 light year diameter might be a misinterpretation: I don't see that number within the actual source, only the radius of which is once again that radius of the area within which is the mass of 1.59 trillion solar masses. I think the 1.59 trillion solar masses is within the 129,000 light year radius. Might be getting redundant, might need to post it on Wikiproject: Astronomy. The Space Enthusiast (talk) 10:59, 6 May 2021 (UTC)
 * I agree that 256,000 light year diameter is a misinterpretation and excessive precision, a press release and subsequent media attention overhyping an academic paper (which is not at all uncommon). The paper is referring to an object that is associated with the Milky Way that is that distance from the Galactic Center. So there's something associated with the Milky Way out there; that doesn't mean it's the radius. In fact, astronomers never give a specific radius for a galaxy except as a very general indicator (which would not be to that precision) because "radius" isn't a simply-defined concept for a galaxy. Instead, we talk about half-light radii or half-mass radii or tidal radii (all of which can be defined quantitatively and measured with reasonable precision, although the Milky Way is the galaxy for which those are most difficult to measure). In all those cases (especially the first two, by definition!), there are some components of any galaxy which are outside the specified characteristic radius, so finding something that's some distance from the center of the Galaxy doesn't mean that the radius of the Galaxy must be larger than that distance. —Alex (Ashill &#124; talk &#124; contribs) 22:28, 6 May 2021 (UTC)

Have we reached a consensus yet? The Space Enthusiast (talk) 23:03, 6 May 2021 (UTC)

Changes on the Lead Article
Hello, I have started this conversation for anyone who would like to discuss on changes of the Lead Article. Pixomite (talk) 23:16, 4 August 2021 (UTC)
 * It helps to be a bit more specific.  thinks that the potential collision between Andromeda and the Milky Way (covered in the Environment section: In 3 to 4 billion years, there may be an Andromeda–Milky Way collision,) should be mentioned in the article's lead. I don't think it's a significant enough aspect of the article to include in the lead. What do other editors thinks?  Schazjmd   (talk)  23:27, 4 August 2021 (UTC)

Size query
Why is the diameter of the Milky Way Galaxy listed as between 170,000 and 200,000 light years, when the web article cited as a reference says the diameter is 100,000 light years?

SENIRAM (talk) 11:18, 23 November 2021 (UTC)

"Amiwarre" listed at Redirects for discussion
A discussion is taking place to address the redirect Amiwarre. The discussion will occur at Redirects for discussion/Log/2021 November 26 until a consensus is reached, and readers of this page are welcome to contribute to the discussion. Certes (talk) 17:05, 26 November 2021 (UTC)

Should our solar system be changed to the solar system
It seems that this violates Wikipedia's neutrality. Thecornerwiki (talk) 01:39, 15 December 2021 (UTC)
 * Its been discussed. Fountains of Bryn Mawr (talk) 01:53, 15 December 2021 (UTC)

Size consensus?
Are we going with this more updated size estimation or not?

https://www.businessinsider.com/milky-way-is-much-more-massive-than-previously-thought-2019-3

There is only brief mention of this much larger size estimation in the article.--Mapsfly (talk) 02:53, 8 January 2022 (UTC)

MILKY WAY GALAXY
— Preceding unsigned comment added by 78.101.22.47 (talk) 09:35, 23 January 2022 (UTC)