Wikipedia:Articles for deletion/List of largest known galaxies


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.

The result was   keep. Consensus herein is for article retention. I highly recommend that discussion about ways to improve the article continue on its talk page. NorthAmerica1000 08:22, 19 December 2014 (UTC)

List of largest known galaxies

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poor references, incorrect information, extremely difficult to properly curate Parejkoj (talk) 00:46, 12 December 2014 (UTC)

Expanding on my rationale above, a list of "largest galaxies" is poorly defined--half light radius, extended stellar halo, ionized gas halo, neutral gas halo, radio emission?--and is very difficult to properly curate, given that astronomers don't typically think in these terms. This list contains several likely examples of citogenesis, like IC 1101, where most online citations probably came from Wikipedia's incorrect size claims. To properly manage this list would require quite a lot of digging around in research papers, including recomputing sizes from old measurements that used old cosmological parameters. - Parejkoj (talk) 00:55, 12 December 2014 (UTC)
 * Note: This debate has been included in the list of Lists-related deletion discussions.  Everymorning   talk  01:05, 12 December 2014 (UTC)


 * Keep and Fix Largest galaxies is a category that can get a lot of secondary sources. Maybe the list should start with the largest known galaxy and work downward. We will still need some criteria for the cutoff, but it is no more arbitrary than a list of largest cities.-- TMD   Talk Page.  01:41, 12 December 2014 (UTC)
 * In an earlier discussion about this article, I've suggested that the cut-off be the typically top-100 listing, as though 100 is arbitrary, it is a widely used cut-off therefore is not something especially parochial to Wikipeida. -- 67.70.35.44 (talk) 05:55, 12 December 2014 (UTC)
 * Keep Per TMDrew, this list while currently in a rather poor state right now could become a worthwhile article with changes. The concept of the article is sound as there are similar successful lists elsewhere such as list of largest known stars. Winner 42  Talk to me!  02:03, 12 December 2014 (UTC)


 * Comment: Please offer some correct secondary sources for the largest known galaxy. All the secondary sources I've looked at claim IC 1101 as having that honor, many citing back to Wikipedia. It very likely isn't the largest known: it is certainly not larger than 1.5Mly by any measure, and not larger than ~360kly by the usual measure of galaxy size. That's why I think this is a perfect example of citogenesis: most secondary sources got their (incorrect) size number from Wikipedia itself! A similar case can be made for many other items on this list, e.g., NGC 262 does not have a 2.6Mly HI envelope, but rather ~600kly (using the ~10arcmin measurement from Morris & Wannier 1979). A critical point here is that one cannot just use the physical sizes from old papers (like Morris & Wannier's 200x300 kpc value), because old papers very likely use a different cosmology, and thus different distances, when calculating those physical values.
 * I'm not sure how I would go about identifying the largest galaxies in a robust manner. One might be able to make some prgress from either NED or the NASA/Sloan atlas, but I don't think you can search the former by size, and the latter doesn't go far enough out to catch enough objects. - Parejkoj (talk) 05:52, 12 December 2014 (UTC)


 * Note: This debate has been included in the list of Science-related deletion discussions. • Gene93k (talk) 02:58, 12 December 2014 (UTC)


 * Comment User:Skyflubber has mentioned that he has a list of 300 galaxies that could be added to the list. If we can prompt him to provide the list he compiled, we can get on to fixing the article up. -- 67.70.35.44 (talk) 05:55, 12 December 2014 (UTC)
 * Keep and fix per the aboves; we can address the nom's concerns by having a list of largest galaxies by type as the first table/section/list on the list article, so that the largest by each criteria is listed. -- 67.70.35.44 (talk) 05:55, 12 December 2014 (UTC)
 * Pinging since he was mentioned. StringTheory11 (t • c) 17:26, 13 December 2014 (UTC)
 * Keep "poor references, incorrect information" - not a valid reason for deletion. WP:SOFIXIT!  Lugnuts  Dick Laurent is dead 07:54, 12 December 2014 (UTC)
 * Delete, since the article at the moment is not just unsourced, but massively inaccurate as well; most of the galaxies listed are nowhere near the largest, as shown at the discussion at Wikipedia talk:WikiProject Astronomy/Archive 15. A completely inaccurate articles does Wikipedia more harm than no article, even on a notable topic, since such articles actively misinform readers on a subject, rather than simply not informing at all. WP:BLOWITUP seems to apply here, since I agree that a good list here would be a great asset, but currently it is in such bad shape that I feel there is no choice unless it can be improved in seven days. StringTheory11 (t • c) 15:49, 12 December 2014 (UTC) Changing to keep based off of the IP's comment below and my implementation of the suggestion. StringTheory11 (t • c) 17:27, 14 December 2014 (UTC)
 * A quick and dirty fix would be to remove the table entries below the "300 BCGs" row, and terminating the table there, with just the Milky Way for reference as anything smaller. -- 67.70.35.44 (talk) 16:24, 12 December 2014 (UTC)
 * I might support that...let's see what others think here though about this suggestion. StringTheory11 (t • c) 17:19, 12 December 2014 (UTC)


 * I originally closed as Keep but was reverted - It would've been nice if asked me to revert as opposed to disruptively reverting anyway! . – Davey 2010  •  (talk)  18:30, 12 December 2014 (UTC)
 * You can't, except in extremely rare cases, tell in half a day if an AfD will go one way or the other; it's not nearly enough time to get an accurate representation of all opinions on the subject, and four votes is also nowhere near enough to SNOW outside of rare cases, such as disruptive nominations. I should have notified you, though, and for that I apologize, but I do object to your language of "disruptively reverting". It is not disruptive to revert a premature close. StringTheory11 (t • c) 20:19, 12 December 2014 (UTC)
 * IMHO I at the time saw it as a clear keep but perhaps I shouldn't have jumped the gun so quick there so I apologize for that, I know some people are adamant that there NAC closure are fine but I'm not - We all make mistakes and I'm always more than happy to revert myself and or relist :), BTW I apologize for the "disruptively reverting" comment - It's been a hectic day and the last thing I wanted is to be reverted, Regards, – Davey 2010 •  (talk)  20:34, 12 December 2014 (UTC)
 * Apology accepted; nobody's perfect. I'm glad we could come to an amicable conclusion here. StringTheory11 (t • c) 17:22, 13 December 2014 (UTC)

Wait, there has been a massive incorrect info in here. The 260 multimillion light year galaxies in my list has sizes measured through the old cosmological constant, that is, H0 = 50 km/sec/Mpc value which is massively incorrect. I tried to recompute it using the value per Planck sattelite, H0 = 67.80 ± 0.77 km/sec/Mpc, and now I've already recomputed 160 of them, and none actually reaches 1 Mly. In fact, none even reaches half of that, with largest being NGC 6872 at 350,000 light years.

If I recomputed all of them, I may say only less than 20 will reach 1 Mly, which is a big hectic. What I will say is that we still don't accurately know the exact mechanisms of a galaxy, given that they're poorly understood. Plus, what is our standard in determining the size of the galaxy? Is it the radio lobe, the stellar halo, the dark matter halo, or what? As far as I'm concerned, the Milky Way is twice the Andromeda's size, and possibly even five times, because the Milky Way has a million light year dark matter halo which is part of the galaxy itself.

I suggest to just keep this list because it's so inaccurate. But it must not be deleted because it's very important. Given the right time then we will put more precise info on there. It all just takes time. I will start another survey again. SkyFlubbler (talk) 00:43, 14 December 2014 (UTC)

NO. Do not delete. It is simply one one the most popular astronomy related lists. Plus, I made lots of improvements in it. Prejkoj, I've asked you this before and I'm gonna ask you again: Don't you think it is better to have the article even though there might be some inaccurate informations? (Answer: It is better to have the article) Tetra quark (talk) 22:16, 17 December 2014 (UTC)
 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.