Talk:Solar mass

Solar symbol rendered as sun emoji on mobile browsers
I noticed that on mobile browsers (chrome and samsung) the solar symbol becomes a sun emoji. This does not look very good. I tested unicode char 2299 and it shows the correct symbol on PC and mobile.

However I have no idea how to modify the special command or macro that does this:

Can someone help please?

Thanks


 * (the unsigned question above added at 14:58, 26 September 2018 by 91.229.57.240, someone at FH Joanneum University of Applied Sciences in Austria.)


 * The  template was corrected on 2011-02-15 to use U+2609 instead of U+2299
 * ☉|U+2609 is the correct Unicode for the "Sun" symbol (used in Astronomy and western Astrology), while ⊙|U+2299 is a visually similar symbol with a different meaning (a mathematical operator).
 * It is common in Unicode for one glyph with multiple uses to have separate a code-point for each use; for example, Latin letter "A" has codepoint U+0041, while Greek letter "Α" has codepoint U+391, and Cyrillic letter "А" has codepoint U+0410.
 * U+2609 is not part of the "emoji" Unicode range, so it should always show the "traditional" dot-in-a-circle sign for the sun. Please file a bug report with your device vendor if it shows an inappropriate glyph.
 * Martin Kealey (talk) 19:59, 3 January 2023 (UTC)

(Mass of Protostar?)
(nonrandom heading inserted ... said: Rursus (bork²) 08:54, 12 March 2009 (UTC))

How Do Find Solar Mass For Protostar?

Thank You.

-Mike

A few points-
 * There are many ways of calculating the mass of our Sun. I suggest adding a few more equalities, complete with derivations or explanations. The derivations are very important, especially for those not familiar with the subject matter.
 * Yes, the Solar Mass does persist as "one of astronomy's ... historical conventions," but it is highly useful because it is so easy to visualize compared to many other celestial masses and is therefore a convention that should stick, at least until we find a more useful one. I would hardly call it an "arcane" convention.
 * It is possible to write a mass as a length through the tools of General Relativity, but it is at best occasionally useful or worthwhile. I suggest making note of this in the article instead of listing it as "common."

Prometheusindisguise (talk) 23:44, 19 January 2009 (UTC)

Re: the "arcane" thing. "solar mass" is used everyday in the peer-reviewed astronomy primary literature, so it doesn't count as arcane in the old-fashioned sense; moreover, "solar mass" is an easy to visualize quantity, so it's not arcane in the esoteric sense either. Besides, the sentence contradicts the first sentence of the article that says the solar mass is a "standard" unit. Therefore, I'm going to delete that whole sentence. Sorry.Warren Platts (talk) 02:19, 30 January 2009 (UTC)

Conventional vs. actual?
Ehhm, it occurred to me that if the Solar mass is used as a nonstandard unit, the size of that unit quantity should be separate from the actual Solar mass, like the metre is standardized on an obsolete value of Earth radius. But that is a scientific ideal, which may or may not be implemented in reality (keeping in mind the science-philosophical and linguistic sloppyness of the current weird IAU definition of planet). So, now: If the earlier, the article should be structured acc2 that there are two "Solar mass" concepts. ... said: Rursus (bork²) 08:54, 12 March 2009 (UTC)
 * is the conventional unit "Solar mass" fixed?
 * or does it bounce around randomly depending on the measurements of the actual Solar mass?

The Solar mass would only change if the gravitational constant (G) changed. The quantity G*M(sun) is known highly accurately from measurement of the orbital parameters of the planets. The value for G is known only to a few significant figures and as such the mass of the sun is only known to roughly the same precision. Unlike the meter, which is now defined in terms of the speed of light (a constant) and a time (a certain number of oscillations of cesium), the suns mass is effectively defined by the standard gravitational parameter (a measured value) and the gravitational constant (another measured value). So, to answer your questions: no, and kind of. 68.197.129.9 (talk) 23:12, 31 March 2009 (UTC)


 * The Solar mass is continually decreasing; about 4 million tons per second due to nuclear fusion, and about 2 million tons per second due to the solar wind. This is negligible compared to the total solar mass for short-term calculations. --IanOsgood (talk) 05:41, 8 July 2009 (UTC)

Stub
Stub category applies to those articles with no more than "rudimentary" information. "While very short articles are likely to be stubs, there are some subjects about which there is very little that can be written."

- Stub

This article is not a stub, there's just not much more that should be written, more could, but it would be "inflation" for the sake of it. If you really think it can never be more than a stub, then Copy to Wiktionary. HarryAlffa (talk) 11:24, 21 September 2009 (UTC)


 * There's quite a bit more that can be written about it, like how the mass was determined, why is the value in this article that way, how it is used, etc. It's like the kilogram article, there is something more to say. 76.66.197.30 (talk) 04:42, 23 September 2009 (UTC)

Use of solar symbol ☉
I'm just curious where it is written that the symbol for the Sun should be written '☉'. It doesn't appear to be an IAU standard even though it is a common astronomical convention. Is there a style guideline somewhere suggesting it's use? Why not simply MSun? Thanks.&mdash;RJH (talk) 22:10, 6 October 2009 (UTC)


 * You could do that (subscript Sun or even subscript S), but when writing on paper I always use the ☉ (as a subscript, which is sometimes not available in electronic formatting). I do the same with the Earth symbol.  Both of those go back to ancient times, I think, so they represent a historical convention.  Both are little-used outside astronomy ... which is a rather narrow field ... so in a lot of electronic presentations I don't have them available.  Since the symbol is used for nothing else, it does make for a certain relief from possible ambiguity.   BSVulturis (talk) 15:26, 14 April 2010 (UTC)

R☉/M☉
Hi, if M☉ is solar masses what is R☉ used in the illustration, maybe this could be added to the Related Units section? Regards Khu  kri  12:26, 16 February 2010 (UTC)
 * I'm guessing that R☉ might be the radius of the sun, but that's just a speculation, someone will need to confirm. 71.113.48.83 (talk) 07:44, 11 March 2010 (UTC)
 * Yup, that's Solar radius. BSVulturis (talk) 15:27, 14 April 2010 (UTC)

Please fix problem causing Yahoo to say that this article says the sun is only slightly over 2000 kg
In Yahoo, if you search for "mass of sun", this article is listed as follows:

"Solar mass - Wikipedia, the free encyclopedia

"Related units|See also|References|Further readingThe solar mass, 1.98892×1030 kg, is the standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies. It is equal to the mass of the Sun, about two...

"en.wikipedia.org/wiki/Solar_mass - Cached"

Note that the 1030 appears as though it were a four digit number equal to 1.03*10^3. Of course, 1.98892 times 1,030 kg is between 2000 kg and 2100 kg and is not really the mass of the sun!

In the actual article, the 30 is a superscript, but it does not display that way in the Yahoo search engine.

If no better solution can be found, this could be fixed by changing the article to say 10^30 with a ^ symbol so that it is clearly an exponential and not a four digit number.

However, I would prefer for the article to continue to look as it does now.

Is there any way to change the article so that it appears as 10^30 in search engines that do not display superscripts, but continues to appear as it does now in Wikipedia?

71.109.155.162 (talk) 17:30, 24 November 2010 (UTC)
 * That is up to Yahoo or Google to fix. 89.217.9.188 (talk) 18:27, 16 January 2015 (UTC)

Value according to sources
Currently, there are two sources cited,


 * the ASA Selected Astronomical Constants pdf file
 * NIST CODATA

the first source specifies the solar mass parameter to $$GM_{\odot} = 1.32712442099 \cdot 10^{20} m^3 s^{-2}$$ and Newton's gravitational constant to $$G = (6.67428 \pm 0.00067) \cdot 10^{-11} m^3 kg^{-1} s^{-2} $$ whereas NIST CODATA's value for G is $$G = (6.67384 \pm 0.00080) \cdot 10^{-11} m^3 kg^{-1} s^{-2}$$.

Apparently the value in this article uses the first source's definition of the solar mass parameter and NIST's value for G to calculate the solar mass:

$$M_{\odot} = \frac{(GM_{\odot})}G = \frac{1.32712442099 \cdot 10^{20} m^3 s^{-2}}{6.67384 \cdot 10^{-11} m^3 kg^{-1} s^{-2} } = 1.98855 \times 10^{30} kg$$

Is there any particular reason or intention why NIST's value for G is used instead of the one from ASA? In my opinion, using the last one would be more consistent than jumping around between different sources with different G values for the same calculation.

2x² (talk) 15:08, 6 October 2014 (UTC)


 * I'm sorry for editing my previous post but I had confused myself and by mistake used a different formula in the demonstration than I calculated the result with. Nevertheless, this didn't change anything about my remark.
 * Thus I'd like to suggest to use for $$G$$ the value given by the same source as the $$GM_{\odot}$$ value, namely the one given in the ASA file:
 * Thus I'd like to suggest to use for $$G$$ the value given by the same source as the $$GM_{\odot}$$ value, namely the one given in the ASA file:


 * $$\begin{array}{rcl} GM_{\odot} & = & 1.32712442099 \cdot 10^{20} m^3 s^{-2} \\ G & = & (6.67428 \pm 0.00067) \cdot 10^{-11} m^3 kg^{-1} s^{-2} \end{array}$$


 * This would yield the following value for the solar mass:


 * $$M_{\odot} = \frac{1.32712442099 \cdot 10^{20} m^3 s^{-2}}{6.67428 \cdot 10^{-11} m^3 kg^{-1} s^{-2} } \approx 1.98842 \times 10^{30} kg$$


 * the uncertainty of which can be obtained by the usual taylor expansion:


 * $$\Delta M_{\odot} = M_{\odot} \sqrt{ \left( \frac{\Delta(GM_{\odot})}{(GM_{\odot})} \right)^2 + \left( \frac{\Delta G}G \right)^2 } \approx 0.00020 \times 10^{30} kg$$


 * Any comments on this are appreciated. If there will again be no reply within a few weeks, I'll proceed on the assumption that there is no disagreement with my suggestion and change the article.
 * 2x² (talk) 21:00, 14 November 2014 (UTC)

July 2019: The mass value listed in Wikipedia is in explicit contrast with the value given in the sources it quotes! At least one of the two sources lists the solar mass as 1.9884(2) *10^30 kg. Please correct the article!

Caption not understandable, Betelgeuse too big?
In the caption to the first diagram:

The Sun (1 M☉) which is not visible in this thumbnail is included to illustrate the scale of example stars.

There is something wrong with this sentence. If the sun is not visible, then in what sense is it included, and how can it illustrate anything? (Indeed, the sun is not visible, either in the thumbnail or in the full-size version of the picture.)

Also, how can Betelgeuse, at 20 solar masses, have a radius that exceeds the earth's orbit? This seems to be wrong by many factors of 10. Or am I so dense? 89.217.9.188 (talk) 18:38, 16 January 2015 (UTC)

Betelgeuse is a red giant star, a different part of a star's evolution than the Sun. While the masses can be compared at any stage of stellar evolution, the radii cannot be compared. — Preceding unsigned comment added by 171.66.209.130 (talk) 17:07, 25 February 2015 (UTC)
 * The Sun is the dot in the center in the full scale image. The size is correct and quite ordinary for a red supergiant. Ruslik_ Zero 15:51, 27 July 2019 (UTC)


 * The diagram illustrates the sizes of the stars, not their masses. The original caption reads "The size of some massive stars compared to our Sun". As an illustration for this article it is confusing. Plumbum208 (talk) 21:03, 27 November 2019 (UTC)

I replaced the image; because it's misleading. The image depicts supergiant stars, which have radii of 1000X larger than our sun, but the mass of those stars is only larger by about 30X. Since this article is about solar mass and not solar radius, this image isn't appropriate. After all, our sun is an sized star, so an image comparing the Sun to supergiants doesn't seem pertinent and encyclopedic. Hadron137 (talk) 21:52, 7 May 2020 (UTC)
 * For reference, the previous image was File:Rho Cassiopeiae Sol VY Canis Majoris - 2019-05-14.svg. Hadron137 (talk) 23:30, 7 May 2020 (UTC)

Clutter
It said, “The value of G is difficult to measure and is only known with limited accuracy in SI units”. I cut out “in SI units” as redundant; if you know the value in SI units, you can convert it to any other unit system, easily enuf. Okay?--Solomonfromfinland (talk) 13:59, 25 August 2020 (UTC)

Nominal or actual
Ten years on the the article still can't make up its mind. Is it about the nominal (IAU-defined unit) mass or the actual mass? The lead says it is a unit and then spends the rest of the article talking about how it is measured and how it varies. The unit is neither measured nor varies; it is defined in terms of an SI base unit, as shown in the infobox and the lead. Lithopsian (talk) 16:12, 2 September 2020 (UTC)

Precision of early estimate
Re this sentence in #History_of_measurement: "The value he obtained differs by only 1% from the modern value, but was not as precise."

Ironically, one can't parse whether the precision of the estimate was "not as precise" as 1% or "not as precise" as modern estimates. If it's the latter, that's a trivial quibble that distracts from the remarkable accuracy of the estimate. If it's the former, it's a confusing and trivial quibble, with no context to compare with the precision of later estimates.

Since there is no significant discussion of precision in the article, I propose removing that clause from the sentence, while retaining the interesting fact that the estimate is within 1% of modern values.

TLDR; should read "The value he obtained differs by only 1% from the modern value." 136.38.3.31 (talk) 22:01, 22 March 2024 (UTC)


 * Agreed, the sentence as it's written does not make sense. If the value differs by 1%, that's its precision. Broc (talk) 11:46, 27 March 2024 (UTC)