Wikipedia talk:WikiProject Astronomy/Archive 28

Asteroid vandalism
Hi guys. Whilst doing something else I ran into which had been apparently blanked and emptied by an IP editor. This is way, way beyond my orbit of competence, but User:Exoplanetaryscience, the creator, thinks that it shouldn't have happened. I've got a ton of other stuff to do at the moment and to be honest I don't really know one end of an asteroid belt from another, could someone take a look? Le Deluge (talk) 20:35, 20 August 2017 (UTC)
 * The asteroids in question: 515 Athalia, 679 Pax, and 152 Atala. Lithopsian (talk) 20:57, 20 August 2017 (UTC)
 * At least two IP editors and  are currently removing Tholen classifications from many asteroid articles and asking that at least one emptied category be deleted. I don't know if their reasons are valid, but they have removed reliable sources giving those categories. StarryGrandma (talk) 21:30, 20 August 2017 (UTC)
 * The db-empty on was me before I started digging into what had happened - feel free to revert it once it's no longer empty.Le Deluge (talk) 22:15, 20 August 2017 (UTC)
 * According to a note by Tholen "I" in the datasets used by the JPL Small-Body Database Browser is not a type of asteroid but means "inconsistent data". StarryGrandma (talk) 22:47, 20 August 2017 (UTC)
 * The same note points out that "U" is a type suffix meaning "an unusual spectrum". A type like CP means C is the most likely type, P is the next most likely type. CPU means the same type but with an unusual spectrum. So categories like Category:CFU:-type asteroids (Tholen) should probably be emptied and deleted also. StarryGrandma (talk) 01:04, 21 August 2017 (UTC)
 * Correct and quite obvious (one may add that ":" means "noise"). I also suggest to ban users like Le Deluge from further editing in astronomy articles since they willing accept damaging articles by reverting without giving a reason and cursing at other editors as being vandalists - all while at the same time admitting to not know what they are doing. -- 2A02:1205:34FD:8EA0:5064:1105:18F4:DBE8 (talk) 15:16, 23 August 2017 (UTC)

Non-autoconfirmed user rapidly reverting edits. Would somebody please step-in to prevent the anon user from dismantling our classification structure on wikipedia? While "I" is not literally a spectral type, and "U", ":", and "::" are just modifiers, our classification system is (was) in line with the Planetary Data System (PDS), JPL Small-Body Database (SBDB), the Lightcurve database (LCDB) and other sources.

I have previously contacted the anon editor (2A02:1205:34FD:8EA0:B0F9:7ADC:2CB3:2F9E and 87.103.40.252 refer to the same editor), but I already had my share of deranged communication for this year, that is, the kind of non-autoconfirmed anon user that first of all suggest to ban other users. Prepare yourself for a pretty inappropriate talk!

My reverts (about 20) are now being reverted by that anon user, for example, this revert for. "AS" (A or S) is a perfectly fine category, identical to, , and the data sheet at PDS. A double categorization could be an option, but this has neither been done by the anon user, nor is it something that can be done partially, as this otherwise only creates inconsistencies. There is no reason to delete "CFU:-type" either; that's would be a very poor solution. Instead, we may want to revise the hierarchy of these categories so that the modifiers (U=unusual spectrum; :=noisy data) are listed in subcategories. Please help to avoid disruption. Thx  R fassbind  – talk  16:45, 23 August 2017 (UTC)


 * Please read WP:NOT. Wikipedia is not an indiscriminate collection of information, in particular it is not a mirror for the PDS. If somebody needs database information and knows what it means and how to handle it, he/she will go to appropriate sources and certainly not to Wikipedia. What a "normal" reader of Wikipedia needs, is a natural language text summing up and explaining these data. Instead, you are misleading them - and, quite frankly, yourself - with copying meaningless database codes which neither you nor the "normal" reader will understand and by falsly creating the impression that something like a "CFU:-type" exists (which it does not, because it is a freely invented thing of yours). If you had written that 1658 Innes is A or S in Tholen classification, that would be acceptable. But you didn't. Because you thought that there is a As subtype (similar as in SMASS) - and that's the impression that you evoke in the reader. Category hierarchies should be devised by people who understand the topic. The wrong/inexistent "type" categories should and will be deleted. Even if they were not invented by errant editors, they would not be suited for a category system, given the small number of their members. -- 2A02:1205:34FD:8EA0:5064:1105:18F4:DBE8 (talk) 17:03, 23 August 2017 (UTC)


 * The obscure editor removes vital information without prior consensus, as done with 1658 Innes (example from above). The asteroid's spectral type, be it AS, A/S or A-or-S, simply disappeared from the infobox and from the categories, while the article's body remains unchanged. This is hardly an improvement; only disruptive. I have already contacted (same link as above) the obscure anonymous editor, who remains far from accommodating, makes wild claims (as above) and uses foul language.  R fassbind  – talk  01:02, 24 August 2017 (UTC)


 * Your ad hominem "arguments" are just proof you have no real arguments. It's embarrassing, please don't do it any longer.
 * Removing false claims from articles (e.g. invented, non-existent spectral types) is an improvement. Do you dissent to deleting the categories for these inexistent Tholen "types"? -- 2A02:1205:34FD:8EA0:D5ED:5321:E974:EAA6 (talk) 02:33, 24 August 2017 (UTC)
 * Whoever you are, please create an account. When you have a variable IP, it's difficult to resolve arguments because you don't have a talk page or other editor-specific place to direct comments. Second, when making major changes (like removing categories, blanking articles, mass undoing edits by another editor), please discuss them FIRST. And lastly, please read WP:BRD. If you get reverted, discuss, do not just re-revert. See WP:EDITWAR.
 * I'm not an asteroid expert, so I don't know whether your edits are correct or not - but I do know the behaviour described is not. The standard action to take to prevent "an ip-hopping editor" (you) from continuing to create disruption is to semi-protect all the articles in question from anonymous edits. You would then be required to create an account before being able to make any edits to them.
 * Since you brought up banning editors, be aware that you can be blocked. Your IPv6 address, which keeps changing, is still linked to your physical connection to the internet - prefix 2A02:1205:34FD:8EA0/64. A range-ban can be issued on that address which will affect only those connected through that endpoint. That's usually only one computer which is using DHCP to obtain random IPv6 suffixes.  Tarl N.  ( discuss ) 03:16, 24 August 2017 (UTC)
 * In the case of 1658 Innes, the spectral type was properly cited per WP:CITE but it appears it was removed anyway. Cited values typically have more weight than unestablished, anonymous opinions, and this type of behavior may be bordering on WP:DISRUPT. Please be more careful about editing cited data, and kindly also take a look at WP:CIVIL. Thank you. Praemonitus (talk) 03:17, 24 August 2017 (UTC)
 * Wikipedia's category system is restricted to describing things in just a couple of words, which means it often struggles to capture the shades of grey and complexity in the real world. I can well understand how discombobulating that fuzziness would be to a mathematical mind. Its main purpose is not to describe articles but to help people find them, and an index prioritises utility, consistency and predictability ahead of strict logic. For instance, such as atheists come under  which clearly makes no sense if you think too hard about it, but it is useful, and that's what matters. I'd view I-type as the asteroid equivalent of atheism and as a non-expert it would seem a useful kind of category to keep. Maybe it needs renaming, but  is kinda wordy - I-type is concise and is consistent with its sister categories.
 * Coming on to the process side, I can only echo Tarl N.'s comments. Wikipedia proceeds by establishing consensus, not by simply deleting categories because WP:IDONTLIKEIT. Perhaps User:Rfassbind could have done more to encourage our anonymous friend to discuss the matter here, but I know what it's like trying to keep up with anonymous edits and frankly if you're not a registered user then you're not encouraging dialogue with the community. It's also a general rule that if there is a dispute then things usually get reverted back to the status quo whilst a consensus is established. What we had here was a category that had not been challenged in over two years since it was created by User:Exoplanetaryscience, a user highly experienced in minor planets and with >12,000 edits, and the IP edit was reverted by User:Rfassbind with nearly 70,000 edits. As a non-expert that suggests to me that there's at least a good argument for the status quo and no reason not to use the status quo as the basis for discussion. So that's why I removed the db-empty and put the category back on 515 Athalia, so that the category wouldn't be deleted because it was empty. Our anonymous friend claims this edit shows me "reverting without giving a reason" -in fact it shows the exact opposite, me giving a reason for the reversion whilst reverted the previous edit without any edit summary. Trying to manipulate the truth like that doesn't exactly help a case, even if there is some merit in the points the anon is trying to raise. I would support semi-protection for these articles. Le Deluge (talk) 13:58, 24 August 2017 (UTC)
 * Our anonymous guest is also on the loose at the German Wikipedia. Same topic. Same insults.  R fassbind  – talk  01:37, 25 August 2017 (UTC)
 * I'm not in favor to semi-protect minor-planet articles, even if this is harder or even painful, as we should welcome scrutiny from as many people as possible in order to improve the overall project. That being said, I'm now being followed and bullied by the anonymous editor on several articles. After I have contacted that person again, there is not much more that can be done to encourage this person to discuss the matter here, or is there?  R fassbind  – talk  15:49, 25 August 2017 (UTC)
 * Admirable sentiments that tend not to survive contact with the real world - usually a few weeks of semi-protection is enough for people like this to get bored. It's not like noone can edit a semi-protected article, they just can't do so anonymously - and there's no real need for anonymity in this case, it's not like editing an article about a repressive government or intimate medical details. As an aside, the IPv4 address is a mobile one from Vodafone Portugal, the IPv6 one is Swisscom, so it looks like maybe someone based in Switzerland decided to mess about on Wikipedia during their holiday? The superficial WP:Wikilawyering makes me wonder if this is someone with a registered name, who's gone anonymous to be WP:DISRUPTive.Le Deluge (talk) 17:14, 25 August 2017 (UTC)

Is this necessary?
Was going through the Unassessed Articles for our project and came across Total eclipses on the Moon, as well as the partial and another variation on the theme. All three were originally split from Solar eclipses on the Moon, which I can sort of see as being useful. However, I think a listing of every partial/total eclipse on the moon is incredibly unnecessary, mostly because it's useless trivia (no one will ever see this sort of thing). Prune, or delete? Primefac (talk) 17:40, 28 August 2017 (UTC)
 * Seems like the split was driven largely by the excessive size of the original article (although not explained by the splitter), and the excessive size of the original article was driven largely by a ridiculous listing of 3,000 years-worth of eclipses. Lithopsian (talk) 13:54, 31 August 2017 (UTC)
 * It probably fails WP:INDISCRIMINATE, but might be suitable for Wikidata. Praemonitus (talk) 15:14, 31 August 2017 (UTC)

OGLE-2007-BLG-349(AB)b naming conflict
Hey! Could I grab some assistance over at OGLE-2007-BLG-349(AB)b? The initial paper refers to the planet as planet "c", whereas some other sources (including the EPE) refer to it as planet "b". I'm not familiar enough with the issue to resolve this, and would appreciate some help from someone more knowledgeable. TheDragonFire (talk) 13:06, 4 September 2017 (UTC)

ISO 4 redirects help!
Thanks. Headbomb {t · c · p · b} 13:25, 31 August 2017 (UTC)


 * Gonna ping here since you've already create a few of those. Maybe this will interest you. Headbomb {t · c · p · b} 02:48, 3 September 2017 (UTC)
 * This is job for a bot. Ruslik_ Zero 20:21, 4 September 2017 (UTC)
 * Why does the template remove "." from the ISO4 codes? See Advances in High Energy Physics but Phys. Rev. C. --mfb (talk) 17:21, 3 September 2017 (UTC)
 * I'm not sure I understand the question. If you mean why do you get prompted to create Adv High Energy Physics but not Adv. High Energy Phys., it's because the former doesn't exists while the latter does. Both redirects should be present, but only one needs to be created. Headbomb {t · c · p · b} 00:15, 4 September 2017 (UTC)
 * Ah, I missed that the redirect exists already. --mfb (talk) 01:43, 4 September 2017 (UTC)

Bibcode bot is back alive!
Just to let you know, User:Δ came up with the fix, and brought back to life! Gonna do a run tonight, so get ready for a bibcodepocalyspe! Headbomb {t · c · p · b} 00:04, 6 September 2017 (UTC)
 * Hurrah! Good work. Modest Genius talk 12:05, 6 September 2017 (UTC)
 * Bibcode Bot rules! Lithopsian (talk) 19:56, 6 September 2017 (UTC)
 * Well I've already seen it hose up math formatting here. So yeah, just dandy. Praemonitus (talk) 04:56, 8 September 2017 (UTC)
 * Still some kinks to iron out. I do review each edit, so I'd have caught it, but you were quicker. For now, I've set the bot to bypass articles with \b and \f in it (on top of many other \letter). Headbomb {t · c · p · b} 10:58, 8 September 2017 (UTC)
 * Is adding a bibcode to cite arXiv templates a known problem? While the value is correct, that template does not recognise the bibcode field.  See chi Cygni for an example. Lithopsian (talk) 20:47, 8 September 2017 (UTC)
 * That's a new one. I'll investigate. Headbomb {t · c · p · b} 21:07, 8 September 2017 (UTC)
 * This is possibly caused by cite arxiv's support of arxiv, rather than eprint like the bot expects. Headbomb {t · c · p · b} 21:09, 8 September 2017 (UTC)
 * This is now fixed. Headbomb {t · c · p · b} 23:16, 8 September 2017 (UTC)

Caelum Bayer Designations
According to Caelum, a number of the Bayer designations assigned by Bode to that constellation are no longer in use. I.e. they do not satisfy WP:RECOGNIZABLE. I searched for a reliable source for the designation Nu Caeli, but couldn't find anything useful. It's not even listed in SIMBAD, which seems to include just about every catalogue of note. Indeed, the name actually seems to have been primarily promoted because of its use in Wikipedia. I'd like to suggest that we rename all Caelum stars with Bayer designations save the six assigned by Lacaille. Praemonitus (talk) 18:29, 9 September 2017 (UTC)
 * Support: I couldn't find reliable sources for Nu Caeli, and also Lambda Caeli. Loooke (talk) 11:59, 10 September 2017 (UTC)
 * Both are listed in Kostjuk (2002), HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index, but certainly not in common use. Lithopsian (talk) 12:07, 10 September 2017 (UTC)
 * ν is also mentioned in the Uranometria Argentina reprint: "The letter Nu was assigned by Bode. It was dropped by Gould because he considered this star to be fainter than magnitude 6, and does not appear in the Uranometria Argentina.  However it remains in occasional current use." current would be 21st century, possibly referring to Wikipedia!  Lithopsian (talk) 12:15, 10 September 2017 (UTC)
 * Here is a fun link showing Bode's chart of Caelum, with a number of other obsolete Greek letters up to at least τ. The star currently described as ν is just to the left of λ, difficult to make out against the drawing.  Compare with ν in Horologium (note, not the modern ν Hor!). Lithopsian (talk) 12:45, 10 September 2017 (UTC)
 * Well it's clear the name itself satisfies the WP notability requirement. But I think it still qualifies as an obscure, secondary designation at best. Wikipedia shouldn't be in the business of promoting unused names. Part of the problem though is that the stars themselves are very obscure, so they are borderline notable at best and don't really have a "common" name other than the one that comes from frequently used catalogue designations. Praemonitus (talk) 15:31, 11 September 2017 (UTC)

Exoplanet numbers
Okay, so I came across Extrasolar planet counts, which is a nifty little template, and I was going to use it on List of exoplanets when I realized that the two sets of numbers were wildly different. The former uses Exoplanet.eu while the latter references the NASA exoplanet archive. I seem to recall a discussion somewhere (most likely on the List talk page) that the Exoplanet.eu archive wasn't overly reliable. I'm coming here to get a consensus on which database we should use so that our numbers are consistent across the various pages. Primefac (talk) 13:26, 8 September 2017 (UTC)


 * There's also Exoplanet.org. The numbers are different between them in large part because they have different criteria for what constitutes a confirmed exoplanet. For example, Eu currently uses 60 Mj, the others are (IIRC) in the 25-30 range. And many people put the brown dwarf cut-off below that, down to a few Mj, so I don't think the concept of an exact number even makes sense. If you want an exact number, then I think you just pick one of them (with definitions and policies) as Wikipedia-wide policy and go with that site, noting that different criteria lead to different results. Tbayboy (talk) 16:54, 8 September 2017 (UTC)
 * In other words, as long as there's a reference backing up the statement being made, no one will care. Makes sense. I'm still interested to see if anyone has a particular preference towards which dbase we "should" use. Primefac (talk) 17:14, 8 September 2017 (UTC)
 * Any number that is used is going to be subject to a lot of caveats. Primarily, that the data is not complete (the template needs to include the words "currently known" somewhere!), and that the difference between "known" and "candidate" should be defined by some sort of probability / likelihood. My view is that you should use the NASA database number, as they are the most likely to be systematic about this (although I haven't looked into the selection mechanisms of any of the databases, so this may not be correct). Thanks. Mike Peel (talk) 21:54, 8 September 2017 (UTC)
 * I have a general preference for the Exoplanets Encyclopaedia as it seems to be more complete, but they all rest on rather arbitrary decisions of what does or doesn't count as a confirmed exoplanet. I don't think it's particularly important which one of those sources we use, as long as it's clearly referenced. Modest Genius talk 10:47, 14 September 2017 (UTC)

Green star (astronomy)
Hi, as explained here this article was proposed on m: Translation of the week/Translation candidates for translation in many languages. The article had however some issues and they were apparently not fully resolved. As a consequence, we had a deletion procedure in Italian that is currently redrafting it. You could probably take a look on enwiki as well. It would be better if some part assumed to be based on original research or not perfectly sourced do not further propagate.--Alexmar983 (talk) 07:34, 14 September 2017 (UTC)
 * What a mess! I looked at this article once before and fled in terror.  Lithopsian (talk) 11:09, 14 September 2017 (UTC)
 * A very strange article. We don't bother having one on 'why the sky isn't brown' or 'why people don't have blue skin'. I suppose it doesn't do much harm, but I don't really see the point either. Is this really a common-enough misconception to merit an article? Modest Genius talk 10:26, 15 September 2017 (UTC)
 * It is a "thing". A number of sources describe certain stars as green.  Then the urban myth busters point out that no star (as an approximately black-body radiator) can actually be green.  An article isn't an unreasonable thing.  Maybe it could be merged?  Definitely it needs serious editing.  Lithopsian (talk) 11:12, 15 September 2017 (UTC)

25640 Klintefelt
Hello. 25640 Klintefelt is apparently a main-belt minor planet and has its own article. However, I am noticing many minor planets don't have their own article and are in a list or table. I may be wrong, but this object does not seem to fit the notability criteria per WP:NASTRO. If not, what does the project want to do with this page? I came across this on New Pages Patrol. Thanks. ---Steve Quinn (talk) 00:08, 18 September 2017 (UTC)
 * Non-notable articles (or uncited stubs containing little more than a definition) like this can be redirected to the list. In most cases that saves having a week-long discussion.  Lithopsian (talk) 09:09, 18 September 2017 (UTC)
 * Redirected. Primefac (talk) 12:47, 18 September 2017 (UTC)

Do articles about galaxy filaments need infoboxes?
Category:Galaxy filaments contains several articles on these filaments, but only one of them (Hercules–Corona Borealis Great Wall) has an infobox, which uses infobox supercluster. Do all of these need infoboxes, too? Loooke (talk) 12:51, 21 September 2017 (UTC)
 * I also forgot to mention voids. The articles Taurus Void has one, as well as the Local Void, but others don't. Loooke (talk) 12:54, 21 September 2017 (UTC)

List of largest stars
Think people here should look at List of largest stars....got to kids edit waring the past month.--Moxy (talk) 12:32, 22 September 2017 (UTC)
 * Protected, talk page discussion started. Please feel free to join in the discussion I started to clear this up. Primefac (talk) 12:47, 22 September 2017 (UTC)

Help
I moved this page to its current title P/2006 VW139. Although this is a correct nomenclature, it was probably not a good idea to do this move. I think it would be best to move the page back to its original title, and seek consensus for a page move, because the page is set up for that other name. I will go over to WP:AN and see if I can get an Admin to move this back. Unless there is an Admin who comes across this section and is willing to do this. Sorry about this.Steve Quinn (talk) 17:37, 24 September 2017 (UTC)
 * An admin moved it back now. --mfb (talk) 19:16, 24 September 2017 (UTC)

Compression (astronomy)
Hello! In the process of de-orphaning things I came across Compression (astronomy) and wondered if anyone here was familiar. I would like to link it somewhere to de-orphan it but can't figure out where. Is it an outdated or deprecated term? Is there somewhere I can merge or redirect it? Is there any suggestion for where I can link to it? Thank you in advance! &spades;PMC&spades; (talk) 09:42, 28 September 2017 (UTC)
 * This looks like it largely duplicates Flattening, especially Flattening. It could be merged or redirected there. Modest Genius talk 09:58, 28 September 2017 (UTC)
 * Wow, that was fast. Thanks! &spades;PMC&spades; (talk) 10:00, 28 September 2017 (UTC)

List of people with craters of the Moon named after them and List of craters on Mars named after people
The discussion at Talk:List of people with craters of the Moon named after them regarding proposed renaming of the two main headers listed above, may be of interest. &mdash;Roman Spinner (talk)(contribs) 15:33, 28 September 2017 (UTC)

NGC 479
Just curious what everyone's thoughts are regarding our newest article on NGC 479, which currently has more pictures than text (four images, three sentences). I ask mainly because I got reverted when I removed the gallery and want to know if I was justified or not. Primefac (talk) 03:02, 8 October 2017 (UTC)
 * A duplicate of the infobox image, a simulated non-free image with no fair-use rationale, and a copyrighted image that will be deleted very shortly? That gallery is living on borrowed time.  Lithopsian (talk) 10:12, 8 October 2017 (UTC)

Starbox parallax calculations
Do we know if the Starbox parallax calculations are accurate? I took a look at Beta Muscae, which has a parallax of $9.55$. If I did the math right, this corresponds to $104.712 pc$ which matches the $105$ listed in the article after rounding. However, when I scale that distribution to light years (&times; 3.2616), I get $341.53 pc$ ($342$), which doesn't match the article value of $340$ after rounding. Perhaps it underwent significant figure truncation? Praemonitus (talk) 19:43, 19 October 2017 (UTC)
 * The distances calculated from parallaxes are rounded based on the parallax margin of error. This is done by Template:ErrorBar2.  In short, the distance is rounded to the significant digit comparable to the margin of error (slightly fudged since it is the reciprocal of the actual margin of error).  For example, if the margin of error in the distance is at least one but less than 10 then the parallax is rounded to the nearest whole number.  If the margin of error is at least 10 and less than 100, it is rounded to the nearest ten.  Since light year margins of error are inevitably bigger than parsec margins of error, light years are often rounded to fewer significant figures than parsecs.  Maybe they should both be founded to the same precision?  Don't see that it would cause any harm, and might save some confusion?  Lithopsian (talk) 20:18, 19 October 2017 (UTC)
 * Okay. Well it would be good if the results matched what you get with the Convert template. Thanks. Praemonitus (talk) 22:23, 19 October 2017 (UTC)

GJ 1068
GJ 1068 was nominated for deletion and was closed as delete, but it never got deleted. Was it just forgotten and left there, or is there some reason why it hasn't been deleted? Loooke (talk) 19:39, 24 October 2017 (UTC)
 * It was deleted by on 4 December 2017, then a new article at the same title was started by  on 23 October 2017. Thanks. Mike Peel (talk) 19:56, 24 October 2017 (UTC)
 * CSD'd. Headbomb {t · c · p · b} 20:42, 24 October 2017 (UTC)
 * Deleted. Graeme Bartlett (talk) 22:59, 24 October 2017 (UTC)
 * These articles also appear to be of dubious notability: Gliese 393, Gliese 555, Gliese 638, Gliese 693, Gliese 754, Gliese 784, Gliese 908, Gliese 1002, and GJ 3737. Most of the references just appear to be to various star catalogues. Praemonitus (talk) 21:04, 24 October 2017 (UTC)

Discussion at List of largest stars
I have started a discussion regarding the creation of some guidelines for the List of largest stars, which has seen a bit of edit warring recently. Please join in the conversation and give your thoughts. Thank you. Primefac (talk) 12:47, 26 October 2017 (UTC)

How to convert geocentric to geographic coordinates?
Does anyone know how to convert geocentric to geographic coordinates? Context: I'm struggling to find the algorithm to convert the locations of astronomical observatories to geographic coordinates in order to display them in the List of observatory codes with template. Thx,  R fassbind  – talk  01:14, 18 October 2017 (UTC)
 * Just guessing: I think the sine is the sine of the angle of the observatory from the centre of the earth. So take the inverse sine to get the latitude ... if the earth was a perfect sphere, so it won't be accurate to many digits. It gives reasonable answers for London, Paris, and Toronto. Tbayboy (talk) 13:16, 18 October 2017 (UTC)
 * It seems MathWorks has a function to do it, but you would still need to know rho (geocentric distance) for each observatory. Do you have that?  ~ Tom.Reding (talk ⋅dgaf)  13:25, 18 October 2017 (UTC)
 * In case you guys like to take a closer look, there is already an opensource project on github that converts from/to MPC's parallax constants (rho_cos_phi, rho_sin_phi). Unfortunately, all I get are gibberish results when I do the calculation for an actual observatory (PS: I'm assuming an average value of 6367447.5 for "height_in_meters").  R fassbind  – talk  17:39, 18 October 2017 (UTC)

I found an algorithm to convert MPC's parallax constants to geographic latitude in degrees for some astronomical observatories (here). My calculated location is within approx. 100 meters from most locations given in the corresponding observatory articles on Wikipedia. However, all locations are systematically off by 20 kilometers or so, for which I do correct. And honestly, I don't know what the hell I'm doing. So if you have an improved/alternative algorithm (i.e. something that can be used to actually calculate coordinates) then I'd be happy to learn about it. Thx,  R fassbind  – talk  01:35, 31 October 2017 (UTC)

Algorithms for Julian Day
I have launched a Request For Comment at Talk:Julian day, after a long discussion with another editor. Basic'ly we agree that a couple of algorithms will work correctly if one "rounds" certain quotients toward minus infinity whether they are positive or negative, but the person whom we cite for the algorithms didn't say that, so the other editor wants us to say that the algorithms are only good for positive Julian Day. We also disagree about whether to write one of the algorithms in a simple way, or using a table of constants instead. Eric Kvaalen (talk) 08:03, 31 October 2017 (UTC)
 * The RFC is at Talk:Julian day. I would suggest you rewrite to RFC to state what the issue is as you have explained here. Without knowing the RFC involves two alternatives it sounds like you are just asking if it is OK to present something that is wrong. StarryGrandma (talk) 20:04, 31 October 2017 (UTC)
 * Thanks for the advice and for correcting my link! I am editing my link above as well (from "Day" to "day"). Eric Kvaalen (talk) 07:15, 1 November 2017 (UTC)

List of craters on Mars named after people
The discussion at Talk:List of craters on Mars named after people regarding proposed renaming of the main header listed above, may be of interest. &mdash;Roman Spinner (talk)(contribs) 01:36, 2 November 2017 (UTC)

Deletion discussion about Loren C. Ball
A deletion discussion regarding an amateur astronomer is taking place at Articles for deletion/Loren C. Ball. Your input is requested. Primefac (talk) 16:17, 6 November 2017 (UTC)
 * It's on the WikiProject Deletion sorting/Astronomy list, along with other astronomy-related AfDs. Praemonitus (talk) 21:03, 6 November 2017 (UTC)
 * So it is. I missed that. I will keep that in mind for future reference (though I will note that it wasn't until I posted here that the discussion suddenly received an influx of participants). Primefac (talk) 22:19, 6 November 2017 (UTC)
 * I didn't notice the most recent astronomy AfDs until your post, ; thanks.  ~ Tom.Reding (talk ⋅dgaf)  22:26, 6 November 2017 (UTC)
 * I would never have noticed the AfD if not for this post. It's a good way of attracting additional comments to an AfD that needs them. Modest Genius talk 11:36, 7 November 2017 (UTC)

Change in sunspot articles
There is a discussion that has been started at Talk:Solar cycle 2, and your input is requested. It involves a change made to the sunspot numbers. Primefac (talk) 14:01, 10 November 2017 (UTC)

Science images from WSC2017
Please take a look in here about newly uploaded scientific images on commons during Wiki Science Competitions 2017.--Alexmar983 (talk) 06:27, 17 November 2017 (UTC)

"Planet Ten" and the Kuiper Cliff
At Planets beyond Neptune the newly proposed "Planet Ten" is listed in the section "Kuiper Cliff". Does this planet function as the likely cause of the Kuiper Cliff or is it not related? If it's not related, this proposed planet should be moved to a different section, instead of sitting in the Kuiper Cliff section, since that has had several proposed planets already that are to cause the Cliff. -- 70.51.45.76 (talk) 19:48, 24 November 2017 (UTC)

Disambiguation links on pages tagged by this wikiproject
Wikipedia has many thousands of wikilinks which point to disambiguation pages. It would be useful to readers if these links directed them to the specific pages of interest, rather than making them search through a list. Members of WikiProject Disambiguation have been working on this and the total number is now below 20,000 for the first time. Some of these links require specialist knowledge of the topics concerned and therefore it would be great if you could help in your area of expertise.

A list of the relevant links on pages which fall within the remit of this wikiproject can be found at http://69.142.160.183/~dispenser/cgi-bin/topic_points.py?banner=WikiProject_Astronomy

Please take a few minutes to help make these more useful to our readers.&mdash; Rod talk 13:12, 3 December 2017 (UTC)


 * I think they're all done now. Lithopsian (talk) 14:10, 3 December 2017 (UTC)
 * Or not, the page is now showing a shorter list. brb.  Lithopsian (talk) 14:11, 3 December 2017 (UTC)
 * The fix tool doesn't find links inside templates. IC 4 is a problem, solution unclear.  See Template:Catalogs.  Lithopsian (talk) 14:35, 3 December 2017 (UTC)
 * I don't have s solution for that one, might be worth asking at WikiProject Disambiguation but thanks for sorting the others.&mdash; Rod talk 14:41, 3 December 2017 (UTC)

WP:AALERTS need some help on Community Wishlist Survey
Many of you use Article Alerts to get notified of discussions (PRODs and AfD in particular). However, due to our limit resources (one bot coder), not a whole lot of work can be done on Article Alerts to expand and maintain the bot. If the coder gets run over by a bus, then it's quite possible this tool would become unavailable in the future.

There's currently a proposal on the Community Wishlist Survey for the WMF to take over the project, and make it both more robust / less likely to crash / have better support for new features. But one of the main things is that with a full team behind Article Alerts, this could also be ported to other languages!

I know I can't imagine the project with the alerts. So if you make use of Article Alerts and want to keep using it, please go and support the proposal. And advertise it to the other astronomy projects in other languages too to let them know this exists, otherwise they might miss out on this feature! Thanks in advance! Headbomb {t · c · p · b} 14:45, 4 December 2017 (UTC)

SoHO image use policy
To my surprise (and that of one commenter) the article on SoHO doesn't have any images taken by the satellite. Before I'm bold and start uploading pictures, I thought I'd ask about whether the permissions are free enough for Wikipedia. The observatory's gallery suggests that images can be used for commercial non-educational purposes (as noted on Template:PD-USGov-NASA) but I'm not sure if that's still too restrictive. I would like to upload images like these from EIT, which I think would add a lot to the article. Warrickball (talk) 21:01, 15 December 2017 (UTC)
 * SoHO images are typically copyright. Your link says images can be used for educational and non-commercial purposes, but that falls short of what is needed for uploading to Commons.  In a few cases, non-free images can be uploaded to local WP sites instead of commons but I don't think that will apply here.  Lithopsian (talk) 21:09, 15 December 2017 (UTC)
 * That's what I suspected. :-/ As a follow on, what if I make my own images from the data?  The image data is publicly accessible through the Virtual Solar Observatory and I've already been able to write a script to fetch the data and plot it.  The raw data needs processing (which I've never done...) but supposing I can get a nice-looking image, can I then release that myself under a commons-friendly licence (e.g. CC BY-SA 4.0)? Warrickball (talk) 21:39, 15 December 2017 (UTC)
 * SoHO themselves say you can't. I know that there are admins on Commons who disagree and would accept such images, but equally there are others who'd delete them in a heartbeat.  I tend to go with what the owner says and in this case the owner says don't do it.  Lithopsian (talk) 21:34, 16 December 2017 (UTC)
 * Ah, I apologize, I went ahead and did it anyway. This is the image, which I accept should probably be deleted. I found the data use policy, which has a similar Commons-unfriendly line as the image use policy. Warrickball (talk) 20:45, 17 December 2017 (UTC)


 * I'm surprised they're not public domain: they're produced by NASA. Or does SOHO have some separate copyright soemhow? - Parejkoj (talk) 19:34, 16 December 2017 (UTC)
 * SoHO is a combined ESA/NASA project. It is only safe to assume that images are freely usable when they are produced solely by NASA, as described in the Commons template.  Much abuse of the "NASA produced it" license on Commons already.  Also don't assume that, for example, Hubble Space Telescope images are free: the final image will often be copyrighted although you're free to make your own highly-similar image from the raw data.  Lithopsian (talk) 21:32, 16 December 2017 (UTC)

Light-years away from ... (?)
While looking at articles about deep-space objects (NGC galaxies, for example) which are written by different authors, I noticed that there are at least 4 different approaches when it comes to writing about distances in light-years. Example:

I am using "away from Earth" in my articles about NGC objects (one editor occasionally changes that to "away from the Solar System").

Is there a consensus which approach should be used? Felix558 (talk) 07:53, 5 December 2017 (UTC)


 * I think "from Earth" is best. "away" alone violates NPOV, and what we measure is the distance to Earth. That is also a reference point that can be used independent of the object. Gaia will bring the uncertainty on the distance to Alpha Centauri in a range where the difference to "the Sun" starts to get interesting. --mfb (talk) 08:07, 5 December 2017 (UTC)
 * Yeah, what he said - "from Earth" Cas Liber (talk · contribs) 10:36, 5 December 2017 (UTC)
 * Thirded. Primefac (talk) 12:38, 5 December 2017 (UTC)
 * ...how does "away" alone violate netural point of view? - The Bushranger One ping only 23:06, 5 December 2017 (UTC)
 * Away from what? From Proxima Centauri b? Sure, no one outside Earth or Earth orbit reads the Wikipedia (yet), but even the ambiguity between "from Earth" and "from the Sun" makes the undefined "away" potentially problematic. In the solar system this matters. --mfb (talk) 00:42, 6 December 2017 (UTC)\
 * ....okay. - The Bushranger One ping only 08:34, 6 December 2017 (UTC)
 * Aren't these typically listed as heliocentric distances? In that case it would be away from the Sun. Praemonitus (talk) 18:03, 5 December 2017 (UTC)
 * I think it would depend on what the literature says. Of course, now that I think about it, I don't recall ever seeing a specified source (it's always just "located Xpc away"). Primefac (talk) 18:27, 5 December 2017 (UTC)
 * I do not understand what is all this about? For an object at such a distance even the best distance estimates have precision not exceeding 10%. So d=40 ± 4 million light-years. The size of Milky Way is ~0.1 million light-years. Does it really matter where this distance is measured from? From the Sun, alpha-Centauri, Orion Nebula or Westerlund 1 star cluster? Ruslik_ Zero 20:17, 5 December 2017 (UTC)
 * Just measure from this point:
 * And include an exact time, because the Earth is rotating, and orbiting the Sun, which is orbiting the center of the Milky way, and the Universe is expanding, and...
 * Okay, just say "from Earth" cuz the rest is pointless. (Sorry, couldn't resist.)  --A&#8239;D&#8239;Monroe&#8239;III(talk)  21:03, 5 December 2017 (UTC)
 * Note that this means beings reading our Wikipedia on other planets will have to do their own additional corrections. Tough.  --A&#8239;D&#8239;Monroe&#8239;III(talk)  21:08, 5 December 2017 (UTC)
 * That is a very WP:CRYSTALBALLish issue though.TR 07:54, 6 December 2017 (UTC)
 * I'm not predicting that extra-terrestrial beings don't exist, just that we shouldn't cater to them. "Earth" covers everyone for EN WP.  Let the little green men start their own LGM WP.  --A&#8239;D&#8239;Monroe&#8239;III(talk)  15:38, 6 December 2017 (UTC)
 * I think 'away' is fine on its own, unless the context calls for a more precise zero point (e.g. objects within the Solar System). As an analogy, aircraft altitudes just state the value, without needing to add 'above sea level' every time. However I don't think we need an overarching policy, this can be decided on a case-by-case basis. Modest Genius talk 12:26, 6 December 2017 (UTC)
 * "Away" by itself is needlessly imprecise with no benefit. For instance, when talking about several nearby galaxies, someone reading a bit quickly may think we're stating successive distances between the galaxies -- each is so far from the last.  Adding "from Earth" has no detriment, and avoids a potential problem.  (I'm okay with leaving it out in cases where space is very precious -- big tables or whatever.)  --A&#8239;D&#8239;Monroe&#8239;III(talk)  15:41, 6 December 2017 (UTC)
 * Context is probably key here as well. I was curious about how often each of these appeared, and found ULAS J0015+01. The entire paragraph makes no sense unless it says "... away from the Milky Way". Primefac (talk) 15:50, 6 December 2017 (UTC)
 * Agree on taking context into account; forcing a rule to ignore that would be disruptive. I'm assuming we'd apply this only as the default use when any might fit.  --A&#8239;D&#8239;Monroe&#8239;III(talk)  17:04, 6 December 2017 (UTC)
 * When it comes to describing deep-space objects (for example galaxies, like in my example above), context is the same in every article (distance measured from Earth). Yet all 4 approaches stated above are used by different authors, and that looks inconsistent, since those articles don't exist on their own - they are part of the same encyclopedia, which should have consistent way of describing same things in articles about same type of objects.  Felix558 (talk) 22:21, 6 December 2017 (UTC)
 * In fact, at least 6 ways for describing distances of deep-space objects are currently used on Wikipedia:
 * {| class="wikitable" style="background: #fcffbb"
 * {| class="wikitable" style="background: #fcffbb"

! Distance from... !! Examples
 * ...light-years away. || NGC 5668, Messier 95
 * ...light-years away from us. || NGC 3115, DDO 190
 * ...light-years away from Earth. || NGC 3021, NGC 498
 * ...light-years away from the Sun. || Coma Berenices (dwarf galaxy), NGC 4147
 * ...light-years away from the Solar System. || NGC 1, Sculptor Dwarf Galaxy
 * ...light-years away from the Milky Way. || NGC 1979
 * }
 * Felix558 (talk) 22:51, 6 December 2017 (UTC)
 * Each paragraph where this might be used defines its context; one style might be preferable over another in each specific context. I don't imagine that's usually the case, especially in the opening sentence of an article, so I'm fine with giving a default recommendation, and have stated it: "away from Earth".  It's just that I'm not fine with making this a rule that must always be obeyed, regardless of the current prose in use or of any unique qualities of the particular subject.  English isn't a programming language.  --A&#8239;D&#8239;Monroe&#8239;III(talk)  01:58, 7 December 2017 (UTC)
 * ...light-years away from the Solar System. || NGC 1, Sculptor Dwarf Galaxy
 * ...light-years away from the Milky Way. || NGC 1979
 * }
 * Felix558 (talk) 22:51, 6 December 2017 (UTC)
 * Each paragraph where this might be used defines its context; one style might be preferable over another in each specific context. I don't imagine that's usually the case, especially in the opening sentence of an article, so I'm fine with giving a default recommendation, and have stated it: "away from Earth".  It's just that I'm not fine with making this a rule that must always be obeyed, regardless of the current prose in use or of any unique qualities of the particular subject.  English isn't a programming language.  --A&#8239;D&#8239;Monroe&#8239;III(talk)  01:58, 7 December 2017 (UTC)
 * Each paragraph where this might be used defines its context; one style might be preferable over another in each specific context. I don't imagine that's usually the case, especially in the opening sentence of an article, so I'm fine with giving a default recommendation, and have stated it: "away from Earth".  It's just that I'm not fine with making this a rule that must always be obeyed, regardless of the current prose in use or of any unique qualities of the particular subject.  English isn't a programming language.  --A&#8239;D&#8239;Monroe&#8239;III(talk)  01:58, 7 December 2017 (UTC)

If the distance to a star has been obtained using Stellar parallax then it should be 'from the Sun' as this is the actual distance being measured (see also the article for the parsec). Other astronomical distance measurements are all measured 'from the Earth'. Cuddlyopedia (talk) 13:00, 20 December 2017 (UTC)

Query about 60/61 Aurigae
Is https://en.wikipedia.org/wiki/Psi8_Aurigae HIP 33064 as it says above:

or HIP 33133 as it says here: https://en.wikipedia.org/wiki/List_of_stars_in_Auriga

ψ8 Aur	ψ8	61		50204	33133	06h 53m 57.07s	+38° 30′ 18.3″	6.46	−0.56	825	B9.5sp...

60 Aur		60		50037	33064	06h 53m 13.37s	+38° 26′ 18.4″	6.32	2.23

https://en.wikipedia.org/wiki/Psi_Aurigae is a little confusing.

listing ψ8 Aurigae ＝ 60/61 Aurigae — Preceding unsigned comment added by 73.129.31.198 (talk) 01:48, 23 December 2017 (UTC)
 * I suspect the Psi Aurigae page is incorrect in referring to 60. Looking at my Uranometria, page 99 volume 1, 60 and 61 are clearly marked as separate stars, with 61 marked as also being named ψ8. I thought there might be some confusion from ψ8 being a binary star, but the apparent separation of components described is under an arcsecond, while 60/61 separation is about a minute. So that isn't where the extra designation comes in. As best I can tell, ψ8 is 61, whereas 60 is not. Tarl N.  ( discuss ) 02:19, 23 December 2017 (UTC)
 * SIMBAD lists '61 Aur' for psi08 Aur. Praemonitus (talk) 21:00, 23 December 2017 (UTC)
 * Bright star catalogue says 60 Aur has sometimes been called ψ8 although it recommends 61 Aur as actually being ψ8. Kostjuk, 2002  prefer 60 Aur as ψ8 and give a list of sources with that usage.  Hence the set index gives both.  The article itself should really say more about this.  Lithopsian (talk) 21:16, 29 December 2017 (UTC)

Original research by user ProtoJeb21
User:ProtoJeb21 is adding WP:OR to articles such as ocean planet, iron planet and mega-Earth. An example of their writing that I removed from LHS 1140 b is "A significant challenge facing any life on LHS 1140 b is the very high gravitational pull. The surface gravity is 3.25 times that experienced on Earth, which is high enough to potentially cause unconsciousness in some humans. Organisms on LHS 1140 b probably won't develop legs, at it would require too much energy to lift each leg up to walk across the surface. Instead, life may develop into legless creatures similar to slugs or worms on Earth."

I haven't gone through all their edits but I suspect there may be even more original research needing to be removed and much of their contributions could be unreliable. Fdfexoex (talk) 20:35, 29 December 2017 (UTC)
 * Yes, the editor is still subtly vandalizing articles. A ban will likely be needed. Praemonitus (talk) 17:51, 1 January 2018 (UTC)


 * To be fair I don't think that particular edit was vandalism - the mass of Kepler 10c has indeed been revised downwards, it's just that the user didn't bother to include a reference to https://arxiv.org/abs/1707.06192 Fdfexoex (talk) 20:37, 1 January 2018 (UTC)
 * Fair enough. I have a distrust of edits that revise cited information when no new citation is provided. Praemonitus (talk) 16:14, 2 January 2018 (UTC)
 * Which is (unfortunatly) fairly justified - "sneaky numbers vandalism" is one of the worst plagues on Wikipedia. - The Bushranger One ping only 19:04, 2 January 2018 (UTC)

Recruit new editors for your project?
Happy new year! I've been building a tool to help WikiProjects identify and recruit new editors to join and contribute, and collaborated with some WikiProject organizers to make it better. We also wrote a Signpost article to introduce it to the entire Wikipedia community. Right now, we are ready to make it available to more WikiProjects that need it, and I’d like to introduce it to your project! If you are interested in trying out our tool, feel free to sign up. Bobo.03 (talk) 19:53, 3 January 2018 (UTC)

Infobox planet NEO section
Hi, I'm suggesting (see the link) adding a section for NEOs, whereby if an NEO related parameter is provided, the closest approach to Earth, the current Torino rating, and maximum Torino rating are displayed. &#x2230; Bellezzasolo &#x2721;  Discuss  11:16, 10 January 2018 (UTC)

NGC navboxes
The NGC navboxes have a problem where some templates like Ngc5 and Ngc80 look different from other ones like Ngc15 and Ngc20. In particular, the former has NGC designations shortened to include just their number whereas the latter has NGC designations unshortened (sort of like 499 vs. NGC 5585). What should be done about this? Loooke (talk) 16:01, 7 January 2018 (UTC)
 * The links should be piped. If you're in an NGC navbox it should be fairly obvious that the links are to NGC objects; additionally, for size/length purposes. Assuming there's no major objections I'll pipe everything tomorrow. Primefac (talk) 14:47, 8 January 2018 (UTC)
 * Pipe them. Nice catch .  ~ Tom.Reding (talk ⋅dgaf)  15:36, 8 January 2018 (UTC)
 * ✅. I also default-uncollapsed Ngc40 & Ngc55, which were the only 2/16 that were default-collapsed.  ~ Tom.Reding (talk ⋅dgaf)  15:11, 11 January 2018 (UTC)
 * Thanks! Loooke (talk) 21:26, 18 January 2018 (UTC)

Proxima Centauri Image Caption
A now somewhat lengthy debate regarding a caption to an ESO orbital plot of Proxima Centauri could use some additional perspectives as its getting rather redundant. Please take a look if you are interested. Thank you. Praemonitus (talk) 04:09, 21 January 2018 (UTC)

Charts comparing solar analogs to the Sun
Every so often I see charts comparing solar analogs to the Sun. Examples are at Iota Horologii, Kepler-29, and 18 Scorpii. Do we really need these comparison charts? Personally I'd just mention somewhere in the article that the star is similar to the Sun, without needing to compare all the properties.

Sometimes these charts are accompanied by very weasel-wordy text, which goes like this: "To date no solar twin with an exact match as that of the Sun has been found, however, there are some stars that come very close to being identical to that of the Sun, and are such considered solar twins by the majority of the public." What to do with this? Loooke (talk) 23:41, 29 January 2018 (UTC)
 * I don't see the need for distance and coordinates in those charts. Praemonitus (talk) 00:21, 30 January 2018 (UTC)
 * Same here, they are fully redundant to the infobox (or, for Kepler-29, inconsistent). --mfb (talk) 03:57, 30 January 2018 (UTC)
 * Remove 'em. If there's a comparison to be made, it can be done in prose (without the weasel words of course). Primefac (talk) 13:41, 30 January 2018 (UTC)
 * Nuke'em. Headbomb {t · c · p · b} 13:44, 30 January 2018 (UTC)
 * Ok, I've removed all of the charts and the accompanying text. Loooke (talk) 20:56, 30 January 2018 (UTC)

Updated: Pages in Category:Astronomy (1 & 2)
A while ago some people found this useful. I updated it at the end of 2017, and just wanted to let those who've used/been using it know. ~ Tom.Reding (talk ⋅dgaf) 14:11, 13 January 2018 (UTC)
 * Could you compile a version without redirects? This would be useful for User:Bibcode Bot. Headbomb {t · c · p · b} 14:31, 30 January 2018 (UTC)
 * .  ~ Tom.Reding (talk ⋅dgaf)  14:59, 30 January 2018 (UTC)
 * ✅! I created the following suite of pages:
 * all listed at the top of each page, for easy navigation.  ~ Tom.Reding (talk ⋅dgaf)  12:48, 31 January 2018 (UTC)
 * all listed at the top of each page, for easy navigation.  ~ Tom.Reding (talk ⋅dgaf)  12:48, 31 January 2018 (UTC)
 * all listed at the top of each page, for easy navigation.  ~ Tom.Reding (talk ⋅dgaf)  12:48, 31 January 2018 (UTC)
 * all listed at the top of each page, for easy navigation.  ~ Tom.Reding (talk ⋅dgaf)  12:48, 31 January 2018 (UTC)

When was the last super blue blood moon?
Hi. My friends over at Reference desk/Science are having difficulty in focusing on what I want to know. Can any of you good people help out?

Thanks. --  Jack of Oz   [pleasantries]  18:16, 26 January 2018 (UTC)


 * Good luck with that. Very different answers depending on your definition for blue moon and super moon, and your location, plus how picky you are about the depth of the eclipse.  FWIW, 1868 doesn't look like a good year: it has a blue moon (two full moons in October for most of the world), but no total (or even partial umbral) lunar eclipses and no eclipses at all in October, so that's a dud.  Lithopsian (talk) 18:47, 26 January 2018 (UTC)


 * It's a pretty meaningless question. Those terms are not well-defined, and seem to be picked arbitrarily by the authors of press releases to make their event sound rarer or more exciting. Supermoon discusses some of the variations defining a supermoon, there are two different definitions of a blue moon etc. Why does anyone care anyway? These are entirely arbitrary categories. Modest Genius talk 20:31, 26 January 2018 (UTC)


 * Ok, let me put it this way. There are different definitions for "super moon" and different definitions for "blue moon".  If we take one of each of those definitions, and ask the question "When did they last coincide?", we can come to a meaningful answer.  Then, if we add total lunar eclipses into the equation and ask "When did a lunar eclipse, super moon and blue moon last coincide?", we can come to a different meaningful answer.  I want that answer.  --   Jack of Oz   [pleasantries]  05:35, 27 January 2018 (UTC)


 * Why? What possible use would it be to anyone? This might help. Besides, you're the one asking the question, so you need to specify exactly which criteria you're using. Modest Genius talk 13:36, 29 January 2018 (UTC)


 * I've seen reports also about 1866. In 1866, there was a full moon on Mar 1st and Mar 31st, over most of the Earth's surface.  There was a total lunar eclipse on Mar 31st, again widely visible.  However, apogee occurred on April 3rd, so it would be hard to call it a supermoon.  The perigees in mid-March and mid-April were also not particularly close ones.  November 22nd 1866 is a decent supermoon candidate, closest perigee of the year and only 5 hours after the full moon.  Lithopsian (talk) 16:04, 1 February 2018 (UTC)

Peer review for David Meade (author)
If anyone wants to give feedback about my article, go to the peer review page and feel free to do so. -- LovelyGirl7  talk  22:45, 1 February 2018 (UTC)

I love Astronomy!
How can I help with WikiProject Astronomy?

(Date: 1-8-2018)

- Out of this World Adventure 🌎 (Talk)
 * You could look at Category:Astronomy articles needing attention and see what you can assist with. Graeme Bartlett (talk) 12:00, 9 January 2018 (UTC)
 * Also, Category:Astronomy articles needing infoboxes has exactly that: astronomy-related articles that need infoboxes. Loooke (talk) 23:08, 9 January 2018 (UTC)
 * A number of which don't satisfy WP:GNG. Praemonitus (talk) 15:50, 11 January 2018 (UTC)


 * There's also CATEGORY: Draft-Class Astronomy articles and CATEGORY: Astronomy stubs -- 70.52.11.217 (talk) 05:15, 3 February 2018 (UTC)

Lua and Stellar Luminosity
It looks like the Lua language supports the math.exp function, so in theory it should be possible to request a Lua module that can convert the log of stellar luminosity ± error margin into L* ± σL * using the appropriate propagation of uncertainty function. How do we feel about that? Sources such as Joffre et al. (2015) present the stellar luminosity in the former format (logL ± e_logL) whereas Wikipedia articles use the latter, so a template conversion of the error margin could be useful for that purpose. (Note that we're already doing something comparable with the parallax -> distance conversion in the starbox.) Praemonitus (talk) 21:36, 16 December 2017 (UTC)
 * I regularly convert published log(L) values into a linear value, but I rarely propagate the error margins.  Partly from laziness, but also because of lingering doubts about what the appropriate propagation function should be.  I know it is well-defined statistically, but astronomical margins of error tend not even to be statistically sound.  This is nicely shown by the parallax example, where we do usually have a statistically sound margin of error in the parallax but even the most likely distance is not a simple inverse of the parallax.  Read for more statistics than you ever wanted to know.  Lithopsian (talk) 21:50, 16 December 2017 (UTC)
 * I understand the conversion is at best an approximation, but as a reader I find it useful to get some idea of the accuracy of the data. Praemonitus (talk) 22:26, 17 December 2017 (UTC)
 * Could also look at bolometric magnitudes which are still sometimes given instead of luminosities. Lithopsian (talk) 19:21, 18 December 2017 (UTC)
 * An alternative could be to use the upper-lower bound method for the propagation of uncertainty. That involves computing the value with the error margin added/subtracted, then perform the exponentiation of the results. Praemonitus (talk) 21:47, 26 January 2018 (UTC)
 * It looks like the technical term for this type of approach is "probability bounds analysis", with the result providing a p-box. Praemonitus (talk) 17:23, 6 February 2018 (UTC)

Please review Herbig-Haro object for GA criteria
Hi

Herbig-Haro object is a former feature article within the scope of WikiProject Astronomy, and was delisted mainly due to insufficient citations. I have been improving the article for some time and citation concerns have been addressed, along with some other improvements. As such, I have nominated it for GA and would like to request willing editors to review it.

Best regards--ubedjunejo (talk) 22:56, 18 February 2018 (UTC)

A link to a DAB page
Baryon asymmetry links to the DAB page metagalaxy (as a pipe from metagalaxies). Can any expert here help solve the problem? Narky Blert (talk) 12:30, 20 February 2018 (UTC)
 * I think the inclusion of that DAB link is a misunderstanding. Metagalaxy is not a synonym for anti-matter galaxy.  Rather it refers to an amalgamation of galaxies, anything from a galaxy group up to the entire observable universe.  For a while, it was theorised that some of these metagalaxies (ie. groupings of galaxies) might be composed of anti-matter and a description of that could have been mis-read.  Lithopsian (talk) 14:38, 20 February 2018 (UTC)

Template:Wikidata redirect on all MP#Rs with a Wikidata item?
As started doing, I figured I'd follow-through and place Wikidata redirect on all of our main Minor Planet #Redirects which have a Wikidata item currently associated with it (secondary/tertiary/etc. #Rs shouldn't have a WD item anyway). Yea/nay? ~ Tom.Reding (talk ⋅dgaf) 19:00, 25 February 2018 (UTC)
 * Hi Tom, and thanks again for helping! I am working through, and I have finished the "early" minor planets that are sorted there. I'm neutral on whether or not redirects should have WD items, though I don't see anything wrong with it. I'm placing the Wikidata redirect rcat on those category entries because I think it's important that editors are readily informed about it when they click on a WD redirect link. Thanks again!  Paine Ellsworth   put'r there  19:34, 25 February 2018 (UTC)
 * Oh I wasn't even aware of that tracking cat! I'm surprised it's so low (~2600)...and most of them aren't even MPs...  ~ Tom.Reding (talk ⋅dgaf)  21:16, 25 February 2018 (UTC)
 * It's worth noting that whether or not Wikidata sitelinks to redirects are good or bad is an open discussion, see d:Wikidata:Requests for comment/Allow the creation of links to redirects in Wikidata. Personally, I wouldn't spend too much time adding/removing them until that's been decided. Thanks. Mike Peel (talk) 20:09, 25 February 2018 (UTC)
 * Excellent! Thank you; that's relevant for many projects.  ~ Tom.Reding (talk ⋅dgaf)  21:16, 25 February 2018 (UTC)

Main image of Pleiades under copyright?
Was just browsing the article on the Pleiades, and I noticed that the main image is from the Digitized Sky Survey, supposedly under public domain because it's sourced from a NASA release. I was surprised, because I thought DSS images were under copyright, and confirmed that they indeed are. I'm not an expert in copyright info, but something seems inconsistent here. Does NASA using the file mean it's no longer under copyright? Did they make a mistake in using a copyrighted file without permission, or did wikipedia make a mistake in assuming that their use permits free usage. Something overall seems somewhat fishy here. BTW while we're at it, there's a few other images coming directly from DSS and such without any such NASA backup in, such as and. exoplanetaryscience (talk) 01:39, 25 February 2018 (UTC)
 * From what I can find, File:Pleiades large.jpg was created by the STScI at Palomar, and is thus released from copyright. We use PD-USGov-NASA because STScI operates under NASA contract NAS5-26555. I cannot speak for other images in Commons:Category:Digitized Sky Survey, however, and it's likely their individual releases would have to be determined. It appears most of the DSS is based off scans by STScI of photographic plates produced by the UK Schmidt Telescope. I don't see how these could be justified for our use, but I could be missing some other detail. — Huntster (t @ c) 02:41, 25 February 2018 (UTC)
 * From what I can find, File:Pleiades large.jpg was created by the STScI at Palomar, and is thus released from copyright.
 * Is that true though? Indeed the DSS Copyright Information expressly states the Palomar data is "copyright © 1993-1995 by the California Institute of Technology" and at the same time as referencing the NASA contract. IANAL, but our very own article on copyright status of work by the U.S. government states in the opening paragraph;
 * Publication of an otherwise protected work by the U.S. government does not put that work in the public domain. For example, government publications may include works copyrighted by a contractor or grantee; copyrighted material assigned to the U.S. Government; or copyrighted information from other sources.
 * This would imply contracted work is not necessarily free of copyright. ChiZeroOne (talk) 12:13, 25 February 2018 (UTC)
 * A very dubious area. There are lots of images hosted at places like STScI, which have been constructed from copyright images (eg. DSS) with the addition of other wavelengths or annotations.  Without being an intellectual property lawyer and examining the small print in minute detail it can be difficult to tell what the status of these images is.  Wikipedia editors have a terrible habit of assuming everything is free unless there is a massive copyright symbol stamped on it in red, but then I guess it isn't their necks on the line.  In this case, there is an image use link right next to the image.  The linked page contains the usual mystifying text about images being credited to STScI being free-to-use and other images *possibly* being copyright.  In this case the image is unhelpfully credited to "NASA, ESA, and AUAR/Caltech".  The credit isn't explicitly STScI, but those institutions are collectively and effectively STScI; they certainly aren't the DSS copyright holders for that image.  I'd say we're good with this one, but then it isn't my neck on the line and I'm not an intellectual property lawyer.  Other cases you'll have to take on their merit, and if an apparently legitimate image owner such as this does state the wrong license terms I don't think we can double-guess them. Lithopsian (talk) 17:03, 25 February 2018 (UTC)
 * Exactly. At the end of the day we have to do our due diligence, but if the releasing entity who is otherwise credible has screwed up their copyright (or lack thereof) claim, there's not much we can do with it. I'm a big proponent of the precautionary principle at Commons, but in situations like this we'd end up deleting a vast swath of the database if we disregard their own statements. — Huntster (t @ c) 13:27, 26 February 2018 (UTC)
 * Just for reference, DSS (not to be confused with the entirely separate and now free-to-use SDSS) images in general are copyright. There is no question about that.  I delete maybe one a week from Commons, but I suspect there are dozens or even hundreds still on there.  They are widely available through apparently-free software like Aladin but are still copyright.  I don't know what the mechanism is for releasing particular DSS images into the public domain as is apparently done by by institutions like STScI and ESO, but I can only assume it is legitimate.  Lithopsian (talk) 17:07, 25 February 2018 (UTC)

Object type of M104?
Please see Talk:List of Messier objects. Input is welcome. --  Toshio   Yamaguchi  10:38, 3 March 2018 (UTC)

Deletion discussion of Spiral galaxy dynamics
Article Spiral galaxy dynamics has been nominated for deletion discussion. Editors interested in the discussion are welcome to share their views on the deletion discussion page. Thanks --UbedJunejo (talk•cont) 19:10, 11 March 2018 (UTC)

Units for equatorial coordinates?
I was trying to look up the location of Orion_(constellation), and the infobox says RA=5, dec=+5. I was not familiar with the equatorial coordinate system, so I clicked through and found that both RA and dec are angles. Shouldn't we provide the units for those angles? In math, angles without units are typically taken to be in radians, but here I guess RA is in hours and dec is in degrees (correct?). The usage instructions for infobox constellation recommend to use the templates RA and DEC which add the proper units automatically. For experts, the assumed units are probably clear, but adding them won't hurt and would make things easier for laymen. Cheers, AxelBoldt (talk) 21:32, 14 March 2018 (UTC)
 * The correct units are hours (h) and degrees(°). I would have thought the infobox should be adding them.  The documentation says those fields expect a range and should use the 0:0:0 and 0° templates, which would provide the units.  A spot-check suggests this isn't happening for many constellations, but is for some (eg. Pavo (constellation)).  Lithopsian (talk) 21:40, 14 March 2018 (UTC)
 * Infobox constellation does not automatically add RA and DEC. Given that either single center coords or ranges are accepted, it wouldn't be practical for the infobox to automatically add the formatting. — Huntster (t @ c) 01:26, 15 March 2018 (UTC)

K2-155d
Hi, I created the article K2-155d but I’m planning big improvements to the article. Today is just a start. Anything I should add in the article (if so feel free to list them down and sources I can use for each of them)? LovelyGirl7  talk  00:48, 22 March 2018 (UTC)
 * I suggest adding links for technical terms like habitable zone and insolation. Is there any information about the orbital eccentricity? Thanks. Praemonitus (talk) 03:35, 22 March 2018 (UTC)
 * I’ve wikilinked the 2 you told me. However, there isn’t really any information about its orbital eccentricity. I can’t find a source that mentions it’s orbital eccentricity, but you could let me know below for a source mentioning it as well as the link for it. Anything else I can add to the article to continue improving it? — LovelyGirl7  talk  11:56, 22 March 2018 (UTC)
 * Thanks. I checked the Hirano et al. (2018) paper and, if I'm reading it correctly, the authors just assumed low eccentricity based on Van Eylen & Albrecht (2015). Praemonitus (talk) 15:32, 22 March 2018 (UTC)
 * I’ve added the source and a sentence saying it. How’s the sentence so far? Also, what else do you think I should add in the article, besides eccentricity (and sources for sugggestions)? I have 2 sections in it as well. — LovelyGirl7  talk  16:33, 22 March 2018 (UTC)
 * Well I don't want to be discouraging here, but for an object with a single scientific study, I'm not sure there is a lot more you could add. At best you can probably expand on the existing information a bit. But I could easily be mistaken, of course. Praemonitus (talk) 15:52, 23 March 2018 (UTC)

Sidereal time article improvements
I have added Sidereal time to the project, have updated the article to use modern, 21st century definitions. I would appreciate it if someone would give the article a rating, and would appreciate suggestions for further improvements. Jc3s5h (talk) 12:38, 24 March 2018 (UTC)

FLC:List of nearest exoplanets
Hey guys, if anyone is interested, I would appreciate feedback for this relevant FLC. Nergaal (talk) 17:29, 25 March 2018 (UTC)

HERO
I just created the stub High-Energy Replicated Optics because I saw a reference to it and wanted a page to explain it. I don't really know anything about astronomy, much less high-energy x-ray astronomy, so eyes would be welcome. - CRGreathouse (t | c) 19:59, 27 March 2018 (UTC)

Re Draft:NGC 2202
I've tagged it with the astronomy wikiproject, did you receive an article alert for this?

It's outside of my knowledge area, would be nice if someone expanded the article or confirmed whether it's appropriate for inclusion in the main namespace.

Thank you.

--Gryllida (talk) 01:32, 28 March 2018 (UTC)
 * I added an infobox, but according to a note in Simbad this object may not even exist. Praemonitus (talk) 02:53, 28 March 2018 (UTC)

Stars and planets and notability
So, I just saw a new article, WASP-79b, about an extrasolar planet, but I notice that its star, WASP-79 does not have an article. So, if an extra-solar planet is notable, does that mean its star is notable too? Oiyarbepsy (talk) 13:04, 30 March 2018 (UTC)
 * No. Many years ago, it was rare for a star to have a known exoplanet, so that in itself tended to create coverage.  No longer, there are now thousands of stars with exoplanets and most of them are just entries in a database.  However, stars with notable exoplanets tend to have been studied a little more than your average star and it may be relatively simple to create a reasonable article.  WP:NASTRO still applies but personally I'm a little more relaxed about an article that actually says something useful about its subject and doesn't quite meet the strict criteria.  A one-liner (with or without starbox) just because the star has an exoplanet tends to go straight to AfD.  In this case, there is zero independent coverage of WASP-79, so certainly not notable other than its exoplanet, hard to imagine what you'd say about it that isn't already in the short paragraph in WASP-79b; the existing redirect seems appropriate.  Lithopsian (talk) 13:26, 30 March 2018 (UTC)

Urgent help needed to fix 5 cosmology errors related to the Big Bang in the article Chronology of the universe
There are quite a few errors/ambiguities in our article Chronology of the universe. Some are actively misinforming readers. They need someone who can fix them.


 * Link: Talk:Chronology of the universe

Please look! Thank you. FT2 (Talk 06:52, 13 April 2018 (UTC)

Duplicated subject?: Yarkovsky effect
Hello. I came across two articles that seem to be a duplicate of the same subject: Yarkovsky effect, and Yarkovsky–O'Keefe–Radzievskii–Paddack effect. Are they different phenomena or should they be merged? Thanks. BatteryIncluded (talk) 18:33, 13 April 2018 (UTC)


 * Different things. Technically, strictly.  The Yarkovsky effect is a linear force.  The Yarkovsky–O'Keefe–Radzievskii–Paddack (YORP) effect is a torque, rotational force.  This could be explained better in the articles, and potentially they could even be merged since the mechanism behind the two effects is the same.  Lithopsian (talk) 19:19, 13 April 2018 (UTC)


 * Related but separate effects, see e.g. . They could merge into a Yarkovsky & YORP effects article, but I suspect that would increase reader confusion more than it clarified things. It's probably safest to keep them separate, but add some comparison with the other effect. <b style="font-family: Times New Roman; color: maroon;">Modest Genius</b> talk 14:33, 16 April 2018 (UTC)

Change of source for number of comets & minor planets/asteroids for Solar System
A proposal to change the source for number of comets & minor planets/asteroids for the article Solar System is placed at Talk:Solar_System. Request comments on the topic please. AshLin (talk) 13:14, 21 April 2018 (UTC)

Plea from a simpleton
Is there a simple red-shift-number-to-universe-age table hereabouts? If not, and it's not at Redshift, could someone create a barebones one there? The talk page comment is at Suggestion to help the simpletons. Shenme (talk) 20:43, 12 March 2018 (UTC)
 * It isn't fixed, so a table might be inappropriate although certainly you can find them (eg here). Hubble's law contains a list of reported values (or ranges) for the Hubble Constant that relates redshift to distance, and also has a graph that effectively shows you the relationship.  Lithopsian (talk) 20:46, 12 March 2018 (UTC)


 * It depends on the cosmology you adopt. There's a reason why astronomers mostly stick to reporting the redshift (an observable) rather than age (an inferred model-dependent quantity). See for some tools for doing the calculation. To answer your original question, anything above a redshift of 6 is within a Gyr of the Big Bang, roughly and assuming concordance cosmology. <b style="font-family: Times New Roman; color: maroon;">Modest Genius</b> talk 14:40, 16 April 2018 (UTC)


 * I created a template that did autoconversion (with optional parameters to change from preset H0 and other tweaks) for z to light-travel-distance (if you subtract this from the current age of the universe, you would get the age at that point) and was working on comoving-distance, but that was deleted at MFD, because it was "math" that they claimed no one would use in an article. -- 70.51.203.56 (talk) 11:26, 2 May 2018 (UTC)

Category:LEDA objects and Category:PGC objects
Aren't these the same catalogue? If so, why are there two different categories for this? Loooke (talk) 23:34, 14 April 2018 (UTC)
 * They certainly would appear to be, but a SIMBAD search for LEDA 36252 (specifically mentioned in the LEDA page), doesn't include a PGC name. Primefac (talk) 00:08, 15 April 2018 (UTC)
 * I think PGC and LEDA names are unified in SIMBAD, which is why if you look up, which is mentioned in Principal Galaxies Catalogue, it gives one of the designations as "LEDA 39058". Loooke (talk) 14:00, 15 April 2018 (UTC)
 * Since LEDA basically turned into PGC, should we merge the former into the latter? I don't see how the one-paragraph page on LEDA can really be expanded, so it might be worth just chucking it into the PGC page. Would allow us to convert/merge the LEDA cat into the PGC cat. Primefac (talk) 15:27, 15 April 2018 (UTC)
 * Yeah, that seems like a good idea. Loooke (talk) 02:39, 19 April 2018 (UTC)


 * Shouldn't all that be covered in a HyperLEDA article? As both articles say that both catalogues have been subsumed into HyperLEDA, it would be LEDA -> PGC -> HyperLEDA. "CATEGORY: LEDA objects" and "CATEGORY: PGC objects" would be category redirects for the HyperLEDA objects category -- 70.51.203.56 (talk) 11:01, 2 May 2018 (UTC)
 * Well, we don't have a HyperLEDA article, but I suppose we could write one, and then merge the contents of both extant pages into it, thereby making the old categories redundant and merge-able into a hypothetical Category:HyperLEDA objects. Primefac (talk) 12:18, 2 May 2018 (UTC)