Talk:Stephenson 2 DFK 1

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On 20 January 2023, it was proposed that this article be moved from Stephenson 2-18 to Stephenson 2 DFK 1. The result of the discussion was moved.

Distance

Are they any distance estimates that are of historical interest? I'm thinking about adding a distance section. Faren29 (talk) 12:40, 21 May 2022 (UTC)[reply]

Of course. The Space Enthusiast (talk) 15:39, 31 October 2022 (UTC)[reply]

Blackhole heart?

A recent video published by Kurzgesagt proposes that Stephenson 2-18 may contain at its core a black hole, as an explanation for its huge mass. Is there any scientific merit to that hypothesis? 2A02:8109:B6C0:45C4:BE8B:603D:B0BC:4E13 (talk) 12:56, 17 December 2022 (UTC)[reply]

At what timestamp in the video? The Space Enthusiast (talk) 03:12, 18 December 2022 (UTC)[reply]

Well it's not reported in any scientific paper so it's WP:OR no matter which way you look at it. VY Canis Majoris (talk) 16:17, 18 December 2022 (UTC)[reply]

Mis-interpretation of a video about an entirely theoretical object that no longer exists. Nothing here that needs to go in this article. Lithopsian (talk) 16:42, 18 December 2022 (UTC)[reply]

The video doesn't give any properly reliable references (as mentioned above), and YouTube is not a reliable source, so does YT channels or users such as Kurzgesagt – In a Nutshell. Even this hypothesis was mentioned in the video, it would be definitively a mistakenly misleading (mis-interpretation) topic (and pure speculation) for the following reasons:

Most reliable scientific papers (if not all but likely) and even the video itself stated black hole stars (most papers usually call these quasi-stars or quasistars) can no longer exist today, except during the history of the early universe. They, however, might still appear observable from Earth over dozens of billions light-years away at the edge of the observable universe (cosmological horizon) due to the finite speed of light (and slow in cosmic scale).
And based on the stellar evolutionary tracks and three luminosities quoted in the article, Stephenson 2-18 likely would have an initial mass of 17 - 40 M_☉ (if non-rotating, and the upper estimate being if the largest quoted luminosity was correct), hence far too light for a quasi-star to form.

Overall, I wouldn't recommend that quote-unquote "hypothesis" to be on this article (and not even in the quasi-star article either), so no. Plus, the video bizarrely gives "overly" large numbers such as 800,000 R_☉ or 10 million M_☉, to which I don't really know where they come from but I might talk about it later. See also WP:RSPYT and WP:RS. ZaperaWiki44^{(✉/Contribs)} 06:57, 19 December 2022 (UTC)[reply]

I think the OP misinterpreted it. The Space Enthusiast (talk) 18:52, 21 December 2022 (UTC)[reply]

Problematic naming

In this article it has been named ‘RSGC2-18’ in the other names section of the starbox and in the beginning of the page. This name has never been used in any reference. Not only to also mention the fact that the name used in the title has never been used either. In the case of this being removed, should we rename it to ‘St2-18’ or ‘Stephenson 2 DFK 1’? SpaceImplorerExplorerImplorer (talk) 13:42, 20 January 2023 (UTC)[reply]

A good designation cross-reference would be useful! It might be best to avoid the RSGC2 designation as much as possible. The one source that explicitly uses it uses RSGC2-18 to refer to Stephenson 2 DFK 18 (the original Stephenson #7, no St2-#), and not to this star.^[1] I agree that we should rename the article to something that actually appears in print. Why not make a formal request and see if anyone objects? Lithopsian (talk) 15:37, 20 January 2023 (UTC)[reply]

I agree, I have just requested a page move. SpaceImplorerExplorerImplorer (talk) 13:42, 20 January 2023 (UTC) 16:39, 20 January 2023 (UTC)[reply]

Gone. Should be re-added without a reliable reference that this designation is both in use and applies to this star. Lithopsian (talk) 15:13, 24 January 2023 (UTC)[reply]

References

^ Humphreys, Roberta M.; Helmel, Greta; Jones, Terry J.; Gordon, Michael S. (2020). "Exploring the Mass Loss Histories of the Red Supergiants". The Astronomical Journal. 160 (3): 145. arXiv:2008.01108. Bibcode:2020AJ....160..145H. doi:10.3847/1538-3881/abab15. S2CID 220961677.{{cite journal}}: CS1 maint: unflagged free DOI (link)

Requested move 20 January 2023

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: moved. (closed by non-admin page mover) Sceptre (talk) 09:37, 10 February 2023 (UTC)[reply]

Stephenson 2-18 → Stephenson 2 DFK 1 – The naming of the title is problematic, it has never been used in any references, St2-18 has been used in two papers although Stephenson 2 DFK 1/D1 is almost always used in papers. SpaceImplorerExplorerImplorer (talk) 16:36, 20 January 2023 (UTC)— Relisting. —usernamekiran (talk) 03:39, 29 January 2023 (UTC)[reply]

Note: WikiProject Astronomy has been notified of this discussion. —usernamekiran (talk) 03:38, 29 January 2023 (UTC)[reply]

I prefer to have it as Stephenson 2 DFK 1. Also the same issue with Westerlund 1-26 (more commonly referred to as just W26 or Westerlund 1 BKS A). SkyFlubbler (talk) 08:58, 5 February 2023 (UTC)[reply]

I support Stephenson 2-DFK 1. The Space Enthusiast (talk) 21:38, 9 February 2023 (UTC)[reply]

Would make sense to have this article renamed as "Stephenson 2 DFK 1" as mentioned above. @SkyFlubbler: I have also left a new topic about renaming the Westerlund 1-26 (and other Wd 1 stars) article as well. Regards—ZaperaWiki44^{(✉/Contribs)} 07:13, 10 February 2023 (UTC)[reply]

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Butter scraped over too much bread

There doesn't seem to be very much mentions of the star in literature, yet the page manages to be several times longer than all the mentions in papers. There are too many sections, they could be shortened down and merged, many just seem to be repeating what has previously been stated in the article.

The reasoning for even meeting the criteria in WP:NASTRO also seems quite circular, the star seemingly only getting famous due to being mentioned on Wikipedia in the first place, and the very likely unreliable radius in the starbox making it the "largest star". VY Canis Majoris (talk) 13:53, 24 January 2023 (UTC)[reply]

I definitely agree with this, this page is indeed ridiculously long. This is a long page about a very obscure star which only has notability because of a likely inaccurate size estimate. This page should be at low-importance, there is practically nothing notable about this star. This page also has many more references than SIMBAD cites. SpaceImplorerExplorerImplorer (talk)

Simbad only list citations for papers that are not largescale surveys. This star, or any other, will be included in data tables in many more papers than Simbad shows. VizieR shows 237 catalogues that include this star! That isn't an exceptional number, some stars are in many more. Lithopsian (talk) 16:55, 24 January 2023 (UTC)[reply]

Being present in a lot of large scale surveys doesn't really make it notable, my guess here is that the sheer number of tables comes from the star being a bright infrared source. VY Canis Majoris (talk) 16:58, 24 January 2023 (UTC)[reply]

Indeed, but offering a comparison of the number of citations in the article to the number of papers listed in Simbad as some sort of metric for the bloatedness of the article isn't very fair. The references given offer valid support for claims about this star, they are not unrelated studies thrown in to try and exaggerate notability as is practice, for example, with certain fringe topics. Lithopsian (talk) 17:46, 24 January 2023 (UTC)[reply]

The article certainly seems several times longer than a bunch of actually notable stars frequently mentioned in literature, as many are either stubs or start class, or don't exist at all. Even some first magnitude stars have shorter pages, like Gacrux. VY Canis Majoris (talk) 18:51, 24 January 2023 (UTC)[reply]

See WP:OTHERSTUFF: nothing you do to this article will make Gacrux any better. Lithopsian (talk) 20:33, 24 January 2023 (UTC)[reply]

It was just an example VY Canis Majoris (talk) 21:26, 24 January 2023 (UTC)[reply]

Either way this page does not meet WP:NASTRO where it states “Coverage must be specific and substantial: notability is not ensured just because an object is listed in a scientific paper or included in a large-scale astronomical survey. To establish notability, the astronomical object must have significant commentary in reliable sources, such as being one of the primary targets of a study with in-depth discussion (beyond discovery and basic parameters). Being listed in a database does not make an object notable. Some astronomical databases and surveys, such as the JPL Small-Body Database, SIMBAD or the Gaia catalogue, list millions or billions of objects. Many objects listed in catalogues and databases have little information beyond their basic parameters and discovery circumstances. Wikipedia does not duplicate content in these databases.”, this star does not have significant coverage in really any papers other than maybe Deguchi et al. (2010) although that paper does not have much ‘dedication’ to St2-18. All references of St2-18 in here only have quick mentions in tables or very small sections. The notability for this object only comes from an inaccurate radius estimate which makes it the ‘largest star known’. While this star is slightly extreme, it quite clearly does not meet the notability guide for astronomical objects. SpaceImplorerExplorerImplorer (talk) 08:39, 25 January 2023 (UTC)[reply]

Based on four research papers (Davies 2007, Deguchi 2010, Negueruela 2013 and finally Humphreys 2020), Stephenson 2-18 is more than slightly extreme. The Space Enthusiast (talk) 04:12, 4 February 2023 (UTC)[reply]

I was mentioning it to be ‘slightly’ extreme based on those papers. This relative amount of extremity does not always make it notable, it would probably make a lot of sense just to merge it into Stephenson 2 with maybe its own section. SpaceImplorerExplorerImplorer (talk) 08:17, 4 February 2023 (UTC)[reply]

There are also several things that seem more relevant to move to the page on Stephenson 2 itself, like historical distance estimates and some of the surveys of stellar content. VY Canis Majoris (talk) 20:27, 24 January 2023 (UTC)[reply]

Hello. I apologize for the bloatedness of the article. After that incident with St2-DFK-18 being confused with this star, I could not let such an incident happen again. Thus, I added stuff to the article to make sure people don’t get confused again. The Space Enthusiast (talk) 14:12, 25 January 2023 (UTC)[reply]

Renaming

IRAS 18362-0607 is a very rarely used name for Stephenson 2 DFK 1. Thus it should not be the article name.--The Space Enthusiast (talk) 02:56, 6 May 2023 (UTC)[reply]

Cannot argue and definitively agree, especially when the said designation was little to no used in most scientific papers. Also, the summary has nothing to do with the page renaming (and is also dumbly unexplained basically). Consider we should revert it ASAP. Regards—ZaperaWiki44^{(✉/Contribs)} 07:31, 6 May 2023 (UTC)[reply]

Merge with Stephenson 2?

This star does not meet WP:NASTRO or WP:GNG because it does not have significant coverage, the biggest mention was a small section in a paper. However, it is considered an ‘interesting’ object since it is relatively extreme, which would therefore make sense to have a section in Stephenson 2 rather than an entire article. The only reason this article exists and is so long is because of a clearly inaccurate measurement that ‘makes it the largest known star’ and makes it much more well-known than it should be. WP:NASTRO already mentions "A single paper is not enough to establish notability. Being mentioned alongside other similar objects, such as in a table of properties of 200 newly discovered supernovae, does not constitute non-trivial coverage.", this star does not meet any of the other criteria either. Shouldn’t it have a section in Stephenson 2 like with RSGC1-F13? SpaceImplorerExplorerImplorer (talk) 06:26, 24 June 2023 (UTC)[reply]

I feel that it already has enough notability. If it was not notable, then I think Negueruela 2013 and Humphreys 2020 would not have mentioned it.--The Space Enthusiast (talk) 01:57, 25 June 2023 (UTC)[reply]

I was saying that it does not have enough notability for a Wikipedia article because it does not have enough significant coverage. Small sections in papers with little mention does not establish notability. Again, the star is notable enough to have a somewhat large section in Stephenson 2. SpaceImplorerExplorerImplorer 06:17, 25 June 2023 (UTC)[reply]

The article is certainly bloated with information that would be better suited for the page on Stephenson 2 itself, and information that could be stated for any star of the same type. I'm surprised the article is longer than that of its supposed cluster. For example, the historical distance estimates apply more to the cluster as a whole and should be moved there. VY Canis Majoris (talk) 08:05, 25 June 2023 (UTC)[reply]

That is true. I was anyway wondering how it got so long. Take the more likely largest known star and more extreme star than St2D1, WOH G64 for example, its page is about half as long and much more notable than St2D1. The only reason this page exists is because it is ‘the largest star’ SpaceImplorerExplorerImplorer 08:22, 25 June 2023 (UTC)[reply]

Don't merge. There are (barely) multiple sources that mention this object specifically, not just as an entry in a database or large table, even if they aren't solely about it. Membership of Stephenson 2 has been questioned, but that in itself is mention in reliable sources. Even as a non-hypergiant foreground object, we might keep it because of the debate that has already taken place about it, but presumably in time it would fade into history as another red giant. If there is material in the article that is commentary rather than content from reliable sources, then that can obviously be removed. The WP:OTHERSTUFF mention of WOH G64 might be taken as an indication of lack of notability for that object: there really is very little published about it, and most of that too superficial to be reliable. What I see in this article is a very complete repetition of just about everything ever published about it. Perhaps a bit of it can be considered cruft, but not huge amounts. Lithopsian (talk) 13:00, 25 June 2023 (UTC)[reply]

Is this discussion still open? because I 101% agree with it. It’s page was only made because of an inaccurate size that everyone believed Atlantlc27Lol (talk) 02:01, 9 December 2023 (UTC)[reply]

RfC: The radius of Stephenson 2 DFK 1

To finally put a formal discussion and an in-depth exploration of all sides regarding the issue of this article (and hopefully a resolution), I am launching an RfC.

Should we put the radius of Stephenson 2 DFK 1 at the current 2,150 R_☉?

SkyFlubbler (talk) 02:20, 19 August 2023 (UTC)[reply]

Note: For context regarding the issue, see the links I have given in the subsection Discussion below. SkyFlubbler (talk) 05:41, 20 August 2023 (UTC)[reply]

Survey

Oppose - this number is not reliable enough and relies on many faulty assumptions (distance, luminosity, and uncertain cluster membership). SkyFlubbler (talk) 02:20, 19 August 2023 (UTC)[reply]
(invited by the bot) Suggest: Include it with attribution & explanation. Don't put it anywhere as an unattributed or unexplained fact in the voice of Wikipedia. If the infobox does not have space for this, don't include it in the infobox. North8000 (talk) 20:38, 22 August 2023 (UTC)[reply]
Same as above. Include it with a caveat mentioning the uncertainties. Just having the radius displayed the way it is almost presents it as if it’s fact, when it’s far from the truth. Don’t remove it entirely. Faren29 (talk) 11:09, 1 September 2023 (UTC)[reply]
Most people probably wouldn't read the caveat and treat the radius as fact anyway. VY Canis Majoris (talk) 16:49, 5 September 2023 (UTC)[reply]
Not our problem. Faren29 (talk) 17:12, 5 September 2023 (UTC)[reply]
Having St2-18 there is like having HD 271832's 4000+ R_☉ there, which is the only radius calculated luminosity and effective temperature in one paper for that star. SpaceImplorerExplorerImplorer 17:18, 5 September 2023 (UTC)[reply]
To be honest we should just remove it (and probably UY Sct) at this point as the evidence is very weak and it having a 50% uncertainty in the distance is nowhere near anything that could challenge the radius and HD limits. We should probably keep WOH G64 as the largest for now as it has strong evidence for being the largest known star and the fact that it has been explicitly mentioned in 3 papers as being a very likely contender for being the largest known star. SpaceImplorerExplorerImplorer 17:59, 22 September 2023 (UTC)[reply]

Discussion

I have changed my view over the past few months, but now I have to concede that this should be addressed now. The radius is so large (even larger than the 2007 VY Canis Majoris estimate) that it is completely baffling and too large to be true. The assumptions on cluster membership, as well as the luminosity, are too big of a stretch that is not worth mentioning for it to have a serious challenge to the Humphreys-Davidson limit of 1,500 R_☉. SkyFlubbler (talk) 02:20, 19 August 2023 (UTC)[reply]
Could you give some background regarding the dispute? Edward-Woodrow :) _[talk] 18:33, 19 August 2023 (UTC)[reply]
If you want a full context regarding the issue, you may want to read these discussions:
Talk:List of largest known stars/Archive 3#St2-18 a foreground star?

Talk:List of largest known stars/Archive 3#Delete Stephenson 2-18 from the list?

Talk:List of largest known stars/Archive 3#Uncertainties again...

Talk:List of largest known stars/Archive 4#Stephenson 2-18

Talk:List of largest known stars/Archive 4#Stephenson 2-18 (again)

Talk:List of largest known stars#Inaccurate radii on the list

Talk:Stephenson 2 DFK 1/Archive 1#Removing radius
SkyFlubbler (talk) 05:39, 20 August 2023 (UTC)[reply]
I have a compromise: What if we just remove the size on List of Largest Known Stars and its own page until a new, more accurate estimate gets released? Atlantlc27Lol (talk) 10:53, 12 September 2023 (UTC)[reply]
The list has a problem with allowing absurd radii anyway, if any more get added, it would probably be a good idea to revise the list and create new 'rules' for what should be added (that make sense and use scientific papers), if many users do not cope with that, it would be better to delete the list. Stephenson 2 DFK 1 lacks notability and is only mentioned with little dedication or in tables in scientific papers and therefore should be deleted. SpaceImplorerExplorerImplorer 15:38, 12 September 2023 (UTC)[reply]

So I will also address the invocation of the WP:NOTRIGHT and the mess that it creates.

Apart from being an essay and not a Wiki policy, I do take issues with this because the uncertainty (upwards to as high as 50% in the distance and doubtful cluster membership) of Stephenson 2 DFK 1 is well-documented and verifiable, and so I don't think we can invoke WP:NOTRIGHT here because this can be easily verified.

This is perhaps regards to why we chose the luminosity of 440,000 L_☉ that gave the radius of 2,150 R_☉ when really we can choose anything as low as 90,000 L_☉ from Deguchi (2010). Is this because it is a newer source? But newer sources like Humphreys (2020) also mention the undertain membership of the star to Stephenson 2. SkyFlubbler (talk) 06:06, 20 August 2023 (UTC)[reply]

I agree. Another thing that could be mentioned is the standards on the list don’t meet WP:TRUTH and are more ad hoc to what should be kept and do not take into account scientific papers (eg. Some stars only have one estimation that is more than 4000 solar radii and would be taken off the list immediately, despite removing St2-18 being WP:TRUTH) which have limits that make sense from previous and persistent observation. The calculated radii might not even meet WP:OR since they are not mentioned in scientific papers explicitly. SpaceImplorerExplorerImplorer 09:30, 20 August 2023 (UTC)[reply]

Small note: the 90,000 L_☉ estimate for Stephenson 2 DFK 1 is an underestimate because it only considers a narrow range of fluxes, and thus only a small fraction of the area under the spectral energy distribution. VY Canis Majoris (talk) 11:37, 20 August 2023 (UTC)[reply]

Then that would be better suited to be the lower range of the estimate, which works as well as what is done in UY Scuti, which retains the 1,708 R_☉ value while the list considers the smaller, 825 R_☉. We can do the same in order to lessen the push for DFK 1 on the radius of 2,150 R_☉. SkyFlubbler (talk) 23:05, 20 August 2023 (UTC)[reply]

Unfortunately there is no other estimate available. VY Canis Majoris (talk) 04:13, 21 August 2023 (UTC)[reply]

Should we really have to include it though? Its just gonna make more people believe its the largest star even though the size is so very unreliable and is an overestimation? Atlantlc27Lol (talk) 10:38, 21 August 2023 (UTC)[reply]

The standards for inclusion on the list don't rely on scientific papers anyway and fail WP:TRUTH. SpaceImplorerExplorerImplorer 11:09, 21 August 2023 (UTC)[reply]

Also, wasn’t there one that claimed it was 474 SR a few years back? Atlantlc27Lol (talk) 10:40, 21 August 2023 (UTC)[reply]

That was for Stephenson 2 DFK 18 and not DFK 1. SpaceImplorerExplorerImplorer 11:10, 21 August 2023 (UTC)[reply]

Again, that still doesn’t mean that it should be added. The standards for inclusion of stellar radii on the list are not consistent with scientific papers that have far more accurate estimations. The fact that the star is 610 solar radii larger than the potential largest star with better observation on the list is ridiculous. SpaceImplorerExplorerImplorer 17:42, 23 August 2023 (UTC)[reply]

[1] Humphreys, Roberta M.; Helmel, Greta; Jones, Terry J.; Gordon, Michael S. (2020). "Exploring the Mass Loss Histories of the Red Supergiants". The Astronomical Journal. 160 (3): 145. arXiv:2008.01108. Bibcode:2020AJ....160..145H. doi:10.3847/1538-3881/abab15. S2CID 220961677.{{cite journal}}: CS1 maint: unflagged free DOI (link)

[1]