Talk:Westerlund 1 W26

Title

Is my title right? Maybe people seem to be confused. I get the title from its name in SIMBAD. You can delete this article and change the title. You can request me anything about this article. Be free. Thank you! Johndric Valdez (talk) 14:25, 12 September 2013 (UTC)

The name won't be familiar to most people, but then the star won't be familiar to most people under any name. It is referred to simply as W1-26 in the papers I have seen, and I certainly wouldn't know that AS in the BKS catalog was the same star. Lithopsian (talk) 10:49, 17 September 2013 (UTC)

Let me restate this more strongly. The name is not wrong, but it shouldn't be the title of this article. No paper published in the last 20 years uses this designation, which is a catalogue number from a 1970 infra-red survey. The star is W1-26 or some variation thereof. Please change it. In addition, you really really really need to get some references for this article. Just creating an article for a star that you are going to claim is the largest known (even if I was the one who originally put it in the largest star list ;)) without anything to back up that claim isn't good enough. Your own research about how quickly this information is taken up as fact across the internet is testament to how strongly it should be supported before it is allowed to stand here. Lithopsian (talk) 10:36, 22 September 2013 (UTC)

Here are original catalogue references for various designations.

Original survey (later referred to as BKS after the three authors), with the designation of the brightest infra-red source as BKS A: http://adsabs.harvard.edu/abs/1970A&A.....4..248B Follow-up, identifying two components to BKS A, referred to in the paper as A(S) and A(N), for south and north: http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1998MNRAS.299L..43C&db_key=AST&nosetcookie=1 Original discovery by Westerlund, stars not individually listed: http://adsabs.harvard.edu/abs/1961PASP...73...51W Westerlund's paper, listing the star as 26: http://adsabs.harvard.edu/abs/1987A&AS...70..311W Lithopsian (talk) 10:52, 22 September 2013 (UTC)

Oh, I'm sorry, but in SIMBAD they have that name. Personally I want to improve this. It took me months of planning before I've created this article. If that's what it is, then it must be. Tell me what must be the title, and I will change it. Thank you anyway. --Johndric Valdez (talk) 11:00, 22 September 2013 (UTC)--

Yes, Simbad names can be a bit funky sometimes. Usually correct in some sense but very often nothing like the designations people actually use. They can be a good guide to the strict usage of names when common usage can be a bit sloppy through familiarity. For example "W" as in W1 is actually used for at least half a dozen different astronomical catalogues, so strictly it should always be at least Westerlund 1-26 (or even the clunky Simbad term Cl* Westerlund 1 BKS AS), but in context W1-26 is what people always use. Would it be appropriate to have a redirect for BKS AS->W1-26? I can't imagine anyone would have gone looking for BKS AS, but now that it is all over the internet, they might. I don't know what the Wiki policy is on this. Lithopsian (talk) 13:04, 22 September 2013 (UTC)

Additional details

I don't have any data concerning the mass & luminosity of this star, plus its parallax and proper motion. I just have the distance. Please give the information to me if you know some details concerning this star. Thank you! --Johndric Valdez (talk) 05:38, 22 September 2013 (UTC)--

The references on the largest star page contain as much physical data as I have been able to find. It is extremely sketchy and poorly defined. Also variable from at least spectral type M2 to M6. Absolute luminosity is pretty much a guess for an almost unique object embedded in nebulosity and visible only in infra-red. Estimates range from slightly over a million times the sun to well under half that. Compare with other red supergiants where luminosities of half a million times the sun are pretty much the max. There are some other papers on radio emissions that I didn't include, also a recent one about Masers that didn't really contain anything concrete. Lithopsian (talk) 13:09, 22 September 2013 (UTC)

Please add a mass. Fig (talk) 18:46, 2 February 2023 (UTC)

New pictures

I was very happy to see that when I've created this article, the Internet was already full of information about this star, in just 1 week. All were stating on how this star and UY Scuti pushed NML Cygni to 3rd place. I've even saw a video on YouTube with this star included. Maybe my phrase "this star has the diameter of 3.54 billion kilometres, corresponding to a volume 16.5 billion times bigger than the Sun" helped it for people to be fascinated at such a large star. But I want it to have more, like adding a size comparison like this one, the Sun and VY Canis Majoris:

Hope anyone give me a size comparison between the Sun and Westerlund 1-26. The picture shows VY Canis Majoris at 2,100 solar radii. Since Westerlund 1-26 is 2,544 solar radii, create another picture like this one, only make it slightly larger. --Johndric Valdez (talk) 05:38, 22 September 2013 (UTC)--

Also, if possible, I would like to see an artist's impression of this star. It will explain what was Westerlund 1-26's true nature is, just like this to VY Canis Majoris (again, because that star was really, and I mean, REALLY famous):

The article explains that VY Canis Majoris throws out lots of its mass in very wild flares of gas and matter surrounding it in an extensive nebula. And this picture visualizes it better, how its nature really is, at least on an artist's impression. To anyone, if you can create a picture like the one above to Westerlund 1-26, here are the clues:

• It must have a nebula surrounding it, like the one above, but more thicker and opaque.
• Nearby bright stars must be seen, as it is in a star cluster.
• It must be redder but brighter to explain its strong radio emission, as it is a radio-emitting star according to some papers.

It's okay even if you don't have one of the pictures I put on request. But if anyone has both of them, that would be better. --Johndric Valdez (talk) 10:25, 22 September 2013 (UTC)--

Splitting hairs

Is it really accurate to say that the star "will soon go Supernova", when it is around 12,000 light years away? It may have gone Supernova millennia ago, but the light just hasn't reached us yet. bd2412 T 17:44, 17 October 2013 (UTC)

It's fine. We always discuss things with reference to our own frame. Any other frame makes no sense. Lithopsian (talk) 23:21, 17 October 2013 (UTC)

Let me state this. Assume that, but because light is the fastest signal, it may gone supernova in the past, and the light still don't reach us. So it's unreasonable to think that the star already gone supernova. We must wait for a signal to come. What we see is what we say as the present, so we see W1-26 as a star still obviously not going supernova, we assume it, presently. ==Johndric Valdez (talk) 08:51, 19 October 2013 (UTC)==

The phrase "go supernova" is an abomination that should never be used. It is like saying that someone will "go dead" or that a bomb will "go explosion". The star is expected to explode as a supernova. 200.111.144.20 (talk) 16:50, 19 October 2013 (UTC)

Introduction picture

A new picture was released by ESO last Wednesday (October 16, 2013) showing Westerlund 1 in infrared. Here's the picture:

It shows a greater detail, but I need help. Choose for the prevailing picture of this article. Is it this new one, or still this?:

I think to join the two pics in here, but it may look ugly, or is it? ==Johndric Valdez (talk) 23:41, 19 October 2013 (UTC)==

Put them both in, but separately. One can stay as the starbox image, and another in the text. Also, W26 isn't one of the green dots in this image, but one of the yellow stars. The intense green dot that looks almost like an artefact is the "Triangular Nebula" discussed in the paper, the star just below it is W25, and the brighter star just below and to the right is W26. Lithopsian (talk) 00:04, 20 October 2013 (UTC)

Really? Thanks. ==Johndric Valdez (talk) 08:59, 20 October 2013 (UTC)==

Binary companion?

New data from ESO shows the ionized nebula in Westerlund 1-26. However, the star will be way too cold to heat up the ionized nebula. Does W1-26 have a binary companion, heating the nebula? ==Johndric Valdez (talk) 09:43, 20 October 2013 (UTC)==

Unknown. All that is known is that there is an (apparent) red supergiant and an ionised nebula. A red supergiant shouldn't be able to ionize a nebula, hence something else is going on. There are a lot of stars nearby perfectly capable of producing such a nebula (W25 is a blue supergiant), but they seem a little distant to be producing this one, hence speculation that there is a very hot star hiding in plain sight. There are no other observations to suggest such a star, and it would have to be very faint to not show up. There are several other, less glamorous, explanations for the ionization of the nebula, and a hot companion to W26 seems the least likely. Lithopsian (talk) 14:33, 20 October 2013 (UTC)

Same designation for neighboring stars?

The stars W25 and W13, neighboring stars of Westerlund 1-26, are also amazing stars. If I get an article of them, are they must be named also the same way as of Westerlund 1-26 (i.e Westerlund 1-25; Westerlund 1-13)? ==Johndric Valdez (talk) 06:28, 30 October 2013 (UTC)==

Yes, unless there is some other compelling designation such as for the magnetar: CXOU J164710.2–455216. Lithopsian (talk) 11:52, 30 October 2013 (UTC)

Number sign

Cygnus OB2 #12, is titled as Cygnus OB2-12 in its article. Since Westerlund 1-26 is in dash sign also, can that mean it's real name is Westerlund 1 #26? ==Johndric Valdez (talk) 06:28, 30 October 2013 (UTC)==

These names are all horribly inconsistent. None of them were meant to be names, just some folks wrote a paper and numbered some objects. Then people afterwards referred to that number in some way or other. Simbad tries to assign unique designations to all those nunbers in papers, but as you've seen that leads to cumbersome names that nobody actually uses. The best we can do is try to follow how most people refer to the stars. In the case of Westerlund 1, they don't use a number sign. Sometimes W1-26, sometimes W1 26, sometimes just W26. We should stick to the same convention for all stars in the cluster. Lithopsian (talk) 11:49, 30 October 2013 (UTC)

Press releases

I'll be honest and up front: I don't like press releases and I don't think they form a suitable basis for statements in scientific Wikipedia articles. In theory they should provide a summary in readable language of more technically complete but difficult to understand publications. In practice they make up almost anything to sound good. This article now includes a case in point: the idea that the nebula around W26 is similar to the nebula around supernova 1987A (and so by implication maybe we're looking at the next supernova, that should get your attention out there in TV dinner land). Too bad it isn't true. That press release is based a particular paper, already referenced on this page, and so the information in it should be derivable from that paper and perhaps some general background information, yet the paper just doesn't say that. The nebula around W26 isn't particularly like that around SN1987A, and I can't find a single statement in any journal to that effect, although it is certainly going to be of interest to investigate their differences and similarities to see whether circumstellar material around supernova progenitors comes from, and hence tie down more closely just what a supernova progenitor looks like. The press release then goes on to say that mass loss leads to the eventual demise of these stars as a supernova, when almost the opposite is true: supernovae occur when stars don't lose enough mass. Mass loss is a hot button research topic right now in large part because there isn't enough of it being observed to account for the observed frequencies of supernovae and the types of progenitors. The background information that could be relevant here is that it is currently thought that stars such as W26 DO NOT explode as supernovae. Instead they lose mass to become a yellow hypergiant, LBV, and finally a Wolf Rayet star. Somewhere along that development they probably do become a supernova but it isn't clear exactly where or exactly what factors decide which stars go bang at which stage. The progenitor of SN1987A was a blue supergiant, possibly an LBV. Lithopsian (talk) 00:56, 2 November 2013 (UTC)

Unknown numbers

I'll get used up, but out of pure curiosity, where in the world did the value of 2,037 solar radii came from? If I assume the star's luminosity somewhere around 400,000 solar I'll get only 1,720 solar radii. When I read the refs I've never seen any "2,037" or something like that. Is it an erroneous number? SkyFlubbler (talk) 09:27, 16 October 2014 (UTC)

A heavily reddened cluster in Ara

Someone (an anonymous editor) has a beef with this phrase. It is a direct quote from the title of the discovery paper and is the only "name" that the cluster has from then until 1998. Edit-warring has got us precisely nowhere. Without wishing to put words into someone else's mouth, there seems to be a belief that the way in which this phrase is presented in the article gives a misleading impression. I would suggest that an editor who finds the current sentence confusing or misleading should rewrite it in a way which they do not find misleading. Not me; I've tried rewriting it twice without success - and I'm probably the one who added it in the first place. Simply removing a clearly cited claim would not seem to be a sustainable option. Lithopsian (talk) 10:42, 5 August 2015 (UTC)

Radius of 2 544 R☉

These refs, , are believed to be the source of the 2,544 R_☉ for Westerlund 1-26. However, every time it was added people would revert it saying that they could not find 2,544 R_☉ at all in the articles. All I could find were:

«Due to their intrinsic luminosity, these stars have such a large physical extent (e.g. ~2,000 R_☉ for the RSG W26 assuming an intrinsic luminosity of log (e.g. L_☉ ∼ 5.8 that any putative companion must be in such a wide orbit that it could not influence their evolution)» -https://www.aanda.org/articles/aa/pdf/2011/07/aa16990-11.pdf So could someone please tell me, how were the 2,544 R_☉ for Westerlund 1-26 calculated? Was it a calculation of the data using the Stefan-Boltzmann law or was it from some other similar source that was similar but deleted? --Joey P. - THE OFFICIAL

The 2,544 number first appeared in an early version of this article, although a different number was in the first created version. Both were given as a range and neither were supported by references. References were added later, but they don't support the radius values in any way. I've tried calculating out various combinations with the data that there is, but I can't get close to those numbers. Since then, they've no doubt been copied all over the web and been memorised as god-given fact. So they keep coming back. For my part, I'll keep deleting them as I can't find any justification even with the most creative interpretation of the data, and nobody has ever given an explanation for them. There is a solid valid explicitly derived in a recent paper (Wright et al, 2013) and nothing else I can find that is really usable. The Clark (2011) value of ~2,000 R_☉ isn't really very helpful since it is just a vague guess based on earlier assumptions about the temperature and very high luminosity (over 1,000,000 L_☉ in early works, and in any case superseded by Wright et al. Lithopsian (talk) 13:51, 8 September 2017 (UTC)

@Lithopsian: According to https://arxiv.org/pdf/1209.6427v1.pdf. The 2,544 R_☉ is probably a poorly calculated value with a brightness of 1,100,000 L_☉ and a temperatue of 3,700 K. In fact, this should give a radius of 2,550 R_☉. ZaperaWiki44^{(✉/Contribs)} 09:05, 16 March 2018 (UTC)

References

Requested move 9 February 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. Consensus to move to Westerlund 1 W26 (closed by non-admin page mover) BilledMammal (talk) 15:58, 26 February 2023 (UTC)

---

Westerlund 1-26 → Westerlund W26 – Basically more or less the same issue that the Stephenson 2-18 article had; the naming of the title is problematic given it has (almost) never or rarely been used for the star in any reliable scientific paper (except for websites which were just based on what is stated on Wikipedia). Instead, most of scientific papers (including modern ones) very commonly refer it to just as "W26" (instead of "Wd 1-26"). In comparison, SIMBAD referred it to as "Westerlund W 26" or "Westerlund 1 BKS AS", although the latter is still overshadowed by the use of the "W26" designation from papers too. The data even does not have "Westerlund 1-26" designation in the star's "Identifiers" section, thus that name might not be notable comparing to others like "W 26" or "BKS A(S)". So, I would probably choose "Westerlund W26" instead. This is the same case for other Westerlund 1 stars such as Westerlund 1-237, Westerlund 1-20, Westerlund 1-75, and Westerlund 1-243 (despite a paper used that said name in the title). Thus, this discussion should also applies to them. Thanks for sharing your thoughts. Regards—ZaperaWiki44^{(✉/Contribs)} 21:04, 9 February 2023 (UTC) — Relisting. Sceptre (talk) 20:23, 16 February 2023 (UTC)

I support the use of both Wd 1 BKS AS and Wd 1 W26, the page does indeed have the same problem as Stephenson 2 DFK 1 did: it is not really a proper identification of the star and is much less common. Although 'Westerlund W26' is not a proper name for the star as it has never been used (Westerlund 1 is the name of the cluster and has been used in papers which quite obviously makes sense). SpaceImplorerExplorerImplorer (talk) 16:09, 10 February 2023 (UTC)

Relisting comment: Would like to see some more input before a closure. Sceptre (talk) 20:23, 16 February 2023 (UTC)

I support a move, but not to Westerlund W26. This would just be swapping one made-up designation for another. At the very least it would need to be Westerlund 1 W26. Simbad does give Cl* Westerlund 1 W 26, but that in itself is just made up to be hyper-unique. Simbad also gives the Cl* Westerlund 1 BKS A, but again it isn't actually used, even without the initial Cl* The literature is quite limited, and most of it uses simple numbers that are understood in context. More popular coverage uses Westerlund1-26 occasionally, but most likely just copied from Wikipedia.

W26 alone might possibly be used as a title - W26 is already a redirect to this page - but people might want that sort of acronym for other purposes in the future, as a dab page. Perhaps W26 with a parenthetical disambiguator? A slightly longer form that is used in the literature is Wd1-26, which would probably be long enough that nobody else would want it. It isn't currently even a redirect to this page, although W1-26 is. Lithopsian (talk) 21:01, 16 February 2023 (UTC)

The use of 'Westerlund 1 W26' (or 'W26') may be a better idea as a title. So, I would agree. Regards—ZaperaWiki44^{(✉/Contribs)} 08:18, 18 February 2023 (UTC)

W26 seems to be a cluster ID used in tables although it may be an actual designation used for the star. For now Westerlund 1 W26 is probably the best title to use. SpaceImplorerExplorerImplorer (talk) 19:42, 21 February 2023 (UTC)

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.

Comments after closure

I've also left a requested move for other Westerlund 1 stars' existing articles such as Westerlund 1-237, 20, 75, and 243 per what I said above. Regards—ZaperaWiki44^{(✉/Contribs)} 13:42, 14 March 2023 (UTC)

@BilledMammal: So I made move requests for Wd1 stars as they did have the same problem as W26, but Lithopsian opposed those requests (see Talk:Westerlund 1-243#Requested move 13 March 2023) and as well as the moving to "Westerlund 1 W26". Despite the discussion about if we should move the page to "Westerlund 1 W26" or "W26" above, "Westerlund 1 W26" (just as with "Westerlund 1-26"), doesn't seem to be used anywhere (except for sources copied from Wikipedia), and we shouldn't be making up designations that was never or little to not in use in the real world. As I mentionned, most papers usually referred this star as W26.

At this point, we should rename the page again, but this time to "W26" simply as it is the best and only title to use (without "Westerlund 1 " term at the beginning of the title, maybe either as a way to refer the star to as a member of Westerlund 1, or to distinguish a hypothetical page with the term "W26"). Regards—ZaperaWiki44^{(✉/Contribs)} 08:17, 18 March 2023 (UTC)

I agree that we should rename it to that, I could only find results for ‘W26’ in scientific papers and the term ‘Westerlund 1 W26’ is only used in SIMBAD without a clear route to where it came from (unless W26 is a cluster ID). SpaceImplorerExplorerImplorer (talk) 09:44, 19 March 2023 (UTC)

Then "W26 (star)" if "W26" is really a cluster ID useless that said "cluster ID" is less notable. Regards—ZaperaWiki44^{(✉/Contribs)} 10:37, 19 March 2023 (UTC)

W26 is not a cluster ID. The cluster is Westerlund 1, or WD1, but nothing with 26 in. Lithopsian (talk) 20:02, 19 March 2023 (UTC)

Simbad tells you where identifiers have come from, although it doesn't always make it clear when it is effectively making up the designation to be unique. If you look in the referenced papers, you can see what they usually use and it tends to be quite cryptic such as W26 or just 26. Later papers that cite the original can be more useful since they are effectively secondary sources, but still they are usually working in a known context and the designations can be very short. Lithopsian (talk) 20:04, 19 March 2023 (UTC)

I suggest waiting for the other discussions to play out. Whatever is decided there would be a strong indicator of what we should do here; we don't have to be strictly consistent but it would be good if we could. Lithopsian (talk) 20:06, 19 March 2023 (UTC)