Talk:Hypergiant

clusters

Some of these "hyper-giants" may in fact be very tight clusters of hot, massive stars surrounded by gas. Eta Carinae has been imaged to multiple IR sources.

Yes, that is possible. But you're wrong about Eta Carinae. It is a single (or double) star, that is known. If I remember correctly, Hubble resolved S Doradus into multiple stars in the early 1990s. Still, S Dor is one of the largest stars known, but not impossibly massive as thought earlier (over 1000 M_Sun).--Jyril 20:20, 18 March 2006 (UTC)

Clarification

According to the article,

Hypergiants are the most luminous stars, thousands to millions of times the solar luminosity; however, their temperatures vary widely between 3,500 K and 35,000 K.

This sentence seems to be saying that there's a relationship between luminosity and temperature in hypergiants that isn't what you would expect. E.g., maybe you would think that a hypergiant would be really hot, but some are only 3,500 K. Is that one of the ideas? I don't feel competent to add this clarification. modify 17:16, 24 June 2006 (UTC)

I assume this is referring the the surface tempereature. The surface of the sun is 5,780 K, but it has a much smaller surface area. — Daniel 21:00, 6 July 2006 (UTC)

This sentence fragment could use rewriting:

the continuum driven stellar winds are extremely rare and are mostly results of theoretical predictions.

For comparison, "unicorns are mostly the results of fictional writing" - arguably true, but I don't think that's what the sentence is trying to convey. Perhaps: "...are understood from the results of..." or some such. 76.254.37.166 (talk) 18:32, 14 February 2009 (UTC)

Size

This article doesn't give a lower limit for a hypergiant's mass. According to the Supermassive star article, stars with masses greater 60 solar masses are hypothetical (one solar mass is equal to the mass of the sun). — Daniel 21:00, 6 July 2006 (UTC)

The theoretical limit mentioned here at 120 solar masses does not match the one mentioned in the LBV section that puts it in 150. I understand this limit varies slightly according to the composition of the star, but this is too much, isn't it? Which one is correct?. - --Acoyauh (talk) 00:22, 18 January 2008 (UTC)

The Eddington luminosity article declines to give a figure, as should both of the articles in question here. Xihr (talk) 02:40, 18 January 2008 (UTC)

The underlying problems for the upper limit are (1) the limit really does depend on the composition; although I don't know the details, a 20% variation seems quite plausible to me (and I do have a solid background in this subject, though no recent involvement); and (2) the analysis you perform tells you an upper limit (Eddington's analysis gives Eddington's upper limit), and there aren't enough massive stars of known mass for us to be confident that there aren't any stars of, say, 170 solar masses -- stars that manage to have some atypical physics working for them (a small black hole at their center, or extraordinary magnetic fields, or something else).

As for the lower limit, that is largely a psychological and social limit: the value that the community of stellar astrophysicists "feels comfortable" with. (If anyone knows of a true change of physics near this mass, please contribute!) The only significance of which I am aware is that above 60 solar masses, you might react with "Gee, that really is a very big one!"

Best not be concerned over the imprecision here. Jmacwiki (talk) 18:42, 7 March 2009 (UTC)

Picture problem

i dont quiet get the pic actually!!!!

Yeah, what's the point of the picture if the planets and suns aren't to scale? 172.200.211.254 (talk) 22:13, 18 November 2007 (UTC)

The point of the picture is for you to see the scale vs the Sun, in this scale the planets don't even ammount to a single pixel. You should get an idea of the scale this way. -- --Acoyauh (talk) 00:17, 18 January 2008 (UTC) 00:15, 18 January 2008 (UTC)

Why can't we just use both pictures? One to compare a hypergiant to the size of the sun, and the other to compare a hypergiant to our solar system's orbits?

Personally, I think the old picture with the orbit comparison gives a more daunting mental image to the titanic size of a hypergiant star. —Preceding unsigned comment added by 71.239.229.213 (talk) 17:44, 30 April 2008 (UTC)

B[e] Hypergiants?

B[e] hypergiants turn up in an ADS search for hypergiants. Can anyone specify what they are? --Keflavich 22:33, 1 May 2007 (UTC)

I believe the notation "B[e]" denotes a star whose atmosphere shows fairly strong absorption lines of ionized hydrogen indicative of a temperature ~ 20-30,000 Kelvin [that's the "B"], with emission lines as well [that the "e"]. Jmacwiki (talk) 18:46, 7 March 2009 (UTC)

I've added HD 169454, ,Zeta-1 Scorpii, BD+14° 5037, MWC 314, and RW Cephei to the list of hypergiant stars; certainly, they're bright (see [[1]], [[2]], and [[3]]). While two of these articles are quite old, newer ones have confirmed the hypergiant nature of these stars.

Nuclear Processes?

I would like to know if a hypergiant (or a red dwarf, for that matter) has any substantial difference in nuclear processes vs. the Sun. SystemBuilder (talk) 22:26, 7 March 2008 (UTC)

This talk page is intended for discussion regarding improvement to the article, not general discussion. You might want to google around for general pages on stellar evolution. Xihr (talk) 22:48, 8 March 2008 (UTC)

Now now! Maybe SystemBuilder asked for such information in the article? This is exactly the correct place for such requests. Said: Rursus (☻) 21:24, 3 November 2008 (UTC)

An article on stellar evolution would be a better place. But at the level of a tiny description: When stars are on the Main Sequence, they "burn" fuel (hydrogen into helium-4) in their cores. Stars of approx. 1 solar mass and less burn it through the "proton-proton" process, whereby direct collisions of protons build up He-4 nuclei. Stars a bit more massive than the Sun burn it through the more efficient but higher-temperature "CNO cycle", a catalytic cycle using proton-capture by Carbon (into Nitrogen, then into Oxygen, and back to Carbon with release of a He-4 nucleus). Other issues apply to non-Main Sequence stars, especially red giants.

That description should at least give you enough keywords for a good Google search to get you started. Jmacwiki (talk) 18:58, 7 March 2009 (UTC)

Other facts?

Should we add the fact that hypergiant stats would last only a few million years in the main part of their lives, and would be even more imaginable in their giant stage? Supergiants only last around 100 million years in their main part, and the sun as a main sequence star 10 billion? 82.12.88.229 (talk) 22:42, 23 March 2008 (UTC)

That is appropriate and relevant info for the article. (Somebody put it there) Said: Rursus (☻) 21:26, 3 November 2008 (UTC)

It Is Been Shown That They Last About 856,000,000 Years.

There is a comment in the article about the short lifetime of hypergiant stars. It is just a vague "few million years", so if anyone wants to reference more precise data, feel free. Lithopsian (talk) 21:37, 23 June 2012 (UTC)

Luminosity class

I am quite new to Wikipedia, so please yell if there is a better place to discuss this on. Xihr, do you have any references for arguing that luminosity class 0 stands for the real hypergiants? According to "The yellow hypergiants" by Cornelis de Jager (1997), all designations (0, Ia0 and Ia+) stands for the same thing, and I haven't found any other articles against that. Actually, Ia+ would probably be the best one, since it is clear that hypergiants are just a small subgroup of the supergiants. Fredrik.Windmark (talk) 21:31, 15 April 2008 (UTC)

This is the right place. No, luminosity class 0 is the hypergiants. Ia is the bright supergiants. Ia+, and Ia-0 are verging classes, where they're in between. This is used throughout the MK system, where X-Y means "something between X and Y," meaning that's it's not quite Y. References are easy to come by; google around for "hypergiant luminosity class 0" (with no quotes) and there are numerous reliable sources that indicate this, including the esteemed Kaler[4]. Think of it this way: If there weren't a difference between Ia+, Ia-0, and 0, then they wouldn't be written differently. Xihr (talk) 06:16, 16 April 2008 (UTC)

Ok, but you can do the exact same thing with Ia0 for example, and get plenty of hits on hypergiants (like David Darlings site [5]). Looking around some on Astro-ph [6] show all three designations for the same thing. The thing with hypergiants is that there is no globally used definition, and quite a lot of different variants are floating around. It is simply not as easy to separate a hypergiant from a supergiant as it is separating a dwarf from a subgiant. And yes, the MKK system would indeed give it 0 if it actually was a distinct group, but many really just want to call it a subgroup of supergiants because of the commonly used Keenan definition, hence Ia0 or Ia+. I think having all three designations in the article would give a more complete view of the subject. Fredrik.Windmark (talk) 07:50, 16 April 2008 (UTC)

The problem with this analysis is that the one quoted citation you used doesn't even include luminosity class 0, but instead stops at Ia-0. X-Y means "X verging on Y," so Ia-0 clearly indicates a luminosity class of "bright supergiant verging on hypergiant." That he didn't mention the clearly implied luminosity class 0 at all isn't dispositive here. Xihr (talk) 20:34, 16 April 2008 (UTC)

The thing is, in this situation, you can't have X verging on Y since we here really don't have an exact definition of Y. Two more articles mentioning hypergiants of various luminosity classes [7] and [8]. The latter is admittedly a bit old, but the point I've been trying to make is that all three definitions are used for the same thing in todays litterature, whether they should be according to MKK or not. I will not take this discussion further, so do what you want. Thanks for the discussion. Fredrik.Windmark (talk) 21:28, 16 April 2008 (UTC)

Table of Extremes

Would it be appropriate and useful to have a Table of Extremes in this article, similar to the one in the Brown Dwarfs article? __meco (talk) 12:04, 12 May 2010 (UTC)

It might be interesting, but with such a limited and poorly defined set of data it wouldn't really be very reliable. The entire list of well-defined hypergiants is only about the same size as the brown dwarfs "extremes" table.Lithopsian (talk) 12:51, 18 May 2012 (UTC)

Need Serious Revisions

This article is very poory written. Example: "Eta Carinae, inside the Keyhole Nebula (NGC 3372) in the southern constellation of Carina. Eta Carinae is extremely massive, possibly as much as 120 to 150 times the mass of the Sun, and is four to five million times as luminous."

First off, try to avoid words such as "extremely" and "possibly". Secondly, there is no source cited. Thirdly, as an astronomer I can tell you that the mass of Eta Carinae is likely around 100 solar masses, however this figure is not well known. Fourthly, the wording is just poor at best. If this article was a paper I would give it a D. Although with grade inflation it would likely end up as a C+, but nevertheless it's very poor. I would consider correcting it myself, but then I wouldn't be surprised if someone changed it right back (I understand this is a common problem on Wikipedia). — Preceding unsigned comment added by Astropi (talk • contribs) 16:48, 21 February 2011 (UTC)

You can still try to put it in. I've run into such things here and there and have been discouraged, but it's still a good thing to make such corrections. You might also be able to help out on something that is bothering me. One part of the article says, "Hypergiants should not be confused with luminous blue variables" while another part says, "Most luminous blue variables are classified as hypergiants." This is at best poorly-written, at worst completely contradictory. Perhaps you can help clarify the sections? Martin Blank (talk) 19:48, 23 March 2011 (UTC)

Hi Martin, yes those statements are contradictory. I re-read the article and it needs so much revision, I'm almost at a loss as to where to start. Currently I'm busy with my own research, but I will try and find the time soon to restart doing a bit of cleaning. — Preceding unsigned comment added by Astropi (talk • contribs) 06:18, 23 September 2011 (UTC)

There's no substitute for doing. So I've made some edits. Far from perfect, I'm sure but perhaps better than before. I also expanded the lists although many of the new stars will not be well known. Lithopsian (talk) 22:59, 20 May 2012 (UTC)

So why not fix it. It's been almost 2 years since the criticism was made and I see not change so far. J.H.McDonnell (talk) 20:54, 19 November 2012 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: no consensus to move. Favonian (talk) 11:21, 5 April 2012 (UTC)

---

Hypergiant → Hypergiant star – According to this CfD "Hypergiant" is ambiguous. Armbrust, B.Ed. ^{Let's talk}_{about my edits?} 13:15, 28 March 2012 (UTC)

Oppose WP:PRIMARYTOPIC. Headbomb {talk / contribs / physics / books} 12:23, 29 March 2012 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

HD 268835

This star has recently been added to the list. I believe it should be removed again. I have never seen a spectral type listed for it that qualifies it as a hypergiant, although I have occasionally seen it tagged with the word hypergiant. It is a B(e) luminous supergiant (=R66). The Wikipedia article for the star describes it as a O-type hypergiant which is incorrect. The spectrum is certainly B, usually given as B8Ia. — Preceding unsigned comment added by Lithopsian (talk • contribs) 10:15, 3 June 2012 (UTC)

Dispute disputed

I dispute the dispute over the factual accuracy of the article and wonder just what statements are in question since referencing seems to be ample. It would seem that after a year's time the accusation/suggestion would be recognized as obsolete. Moreover it would seem that a year is way more than enough time for who ever made such an entry to have corrected the matter. J.H.McDonnell (talk) 19:46, 19 November 2012 (UTC)

I have heavily edited this article this year and added many citations. Any tags from last year probably no longer apply. Lithopsian (talk) 19:59, 19 November 2012 (UTC)

I'm removing that very old tag. If anyone still wants to dispute, feel free. Lithopsian (talk) 16:07, 23 January 2015 (UTC)

Error

Cited statement: "Astronomers are mostly interested in these stars because they relate to understanding stellar evolution, especially with star formation, stability, and their expected demise as supernovae, or even hypernovae." This contention has been already added and reverted several times by LightandDark2000[9][10][11] are incorrect. Saying in the edit summary "Hypernova are much more powerful versions of supernovae, so there's no reason why hypergiants can't explode as hypernovae. Also added a source this time." Untrue and the source doesn't say this. Even the abstract says "The progenitor of supernova SN 2005gl was proposed to be an extremely luminous object, but the association was not robustly established (it was not even clear that the putative progenitor was a single luminous star)."

Because of this, I've added the tag 'failed verification.' (I have also updated SN 2005gl and cited it.) Arianewiki1 (talk) 23:06, 7 April 2019 (UTC)

I note that LightandDark2000 has been properly informed of this problem on their talkpage, but has openly decided to delete it[12] and claims: "I have corrected the terminology errors" They have not done this. According to "Do NOT revert me if I delete your comments, just for the sake of forcing me to read them. If you do this, not only will you be reverted, but you will also likely get reported to the administration."[13], but this irregular kind of avoidance behaviour appears in this latest series of edits just to avoid reasonable scrutiny This edit is unjustified and should be reverted. Hypergiants form normal supernovae, and unless it is proven by a relevant cite has no place here. (If they perceive this as a threat, I'm happy to be, as they threaten, to be "reported to the administration." Feel free to do so.) Arianewiki1 (talk) 07:54, 8 April 2019 (UTC)

Regardless of any of our opinions, if the statement is uncited it should be removed. So far no citation has been provided to support this claim. The association of SN 2005gl with a hypergiant or luminous blue variable progenitor is not relevant since it was not a hypernova or even a particularly luminous supernova. The citation could be used as the best example of a hypergiant producing a supernova in the real world. Lithopsian (talk) 13:44, 8 April 2019 (UTC)

@LightandDark2000: Any comment? Added source that suggests hypergiants only produce ordinary supernova. Further disputes on this topic should be made here instead of making reverts to the main article, but consensus will likely have to be shown if it were to be again added. Thanks. Arianewiki1 (talk) 01:57, 9 April 2019 (UTC)

Section : Relationships with Ofpe, WNL, LBV, and other supergiant stars

I've carefully read this article section several times finding lots of contradictions and broad unsubstantiated statements. It certainly needs reworking and cites to verify some unfounded statements. Worst it reads like an astrophysical university text than towards any average reader. I also find it is wordy and has parts that do not seem even relevant to the subject matter. Example of some serious issues include:

• I've made some simplifications here and there, removed the over used word 'characteristic', and questioned the text with cite required or the dubious / odd sentence "Lower mass LBVs may be a transitional stage to or from cool hypergiants or are a different type of object." (which read like higher-massed LBV are even bigger than hypergiants?)

• Paragraph 5 states: "High rotation rates cause massive stars to shed their atmospheres quickly and prevent the passage from main sequence to supergiant, so these directly become Wolf–Rayet stars." Surely, most of the mass loss is caused by the radiation pressure expelling the outer photosphere into space with rotation being fairly trivial. (Who says this anyway? The main Wolf-Rayet article does say this. In fact, "Stellar mass loss produces a loss of angular momentum and this quickly brakes the rotation of massive stars." is openly a contradiction. Angular momentum evolution mentioned is not necessarily related to mass loss but also the differential rotation of the core and convective zone)

• The next lines says : "Wolf Rayet stars, slash stars, cool slash stars (aka WN10/11), Ofpe, Of+, and Of* stars are not considered hypergiants. Although they are luminous and often have strong emission lines, they have characteristic spectra of their own." If they are not considered Wolf-Rayets, why does it appear here?

• Even stranger, the Wolf-Rayet article only comment about this appears under 'Current models' and says:"Some explode while at the yellow hypergiant or LBV stage, but many become Wolf Rayet stars." but it is not cited, and the Wolf-Rayet article reference [77] 'Fundamental properties of core-collapse Supernova and GRB progenitors: predicting the look of massive stars before death' (2013)[14] doesn't imply this at all. ) This article only says: "Stars finishing their lives as yellow luminous stars have been customarily classified as yellow supergiants (YSG); see e.g. Elias-Rosa et al. (2009, 2010); Fraser et al. (2010); Maund et al. (2011); Georgy (2012). However, we suggest here that some of these stars are actually yellow hypergiants (YHG)." Interesting idea, but this is not citable evidence to support the statement . Hypergiants are only mentioned twice. It seems much of this 2018 cited article has been massaged into the whole section. (See pages 20-22.)

Perhaps the first two paragraphs should be retained and the rest removed? Certainly, Paragraph 3 could be removed without any problems, and it in not very clearly explained how this text is related to yellow hypergiants.

So how do we fix this? Arianewiki1 (talk) 01:43, 9 April 2019 (UTC)

AE Andromedae

The article for this stars states it's an LBV variable!?

And it has mass of 120 solar radii!?

So ... is it one, or is it not!?

Should it be added to the list, or not?????

Please clarify this!

Thanks!

PMurthy1011 (talk) 10:22, 26 June 2020 (UTC)

Confusion about RW Cephei

What is RW Cephei supposed to be? It's parameters are just a mess.

1.) It's smaller size is too small for a red hypergiant.

2.) It's larger size is to big for a yellow hypergiant.

3.) The star's range is huge, and (even though I did this), you can't exactly use it's mean temperature to create a new class altoghether.

Should it even be on the article?! I'm just gonna remove it from this article until this is cleared up and I would like an answer here.

Thanks!PNSMurthy (talk) 04:23, 29 June 2020 (UTC)

Is WOH G64 a hypergiant?

It is listed as a hypergiant on this page, but not on either its page, and there is no citation for it. Should we remove it, keep it, or try to cite it? Atlantlc27Lol (talk) 00:06, 18 December 2023 (UTC)

Nevermind, it was removed. Atlantlc27Lol (talk) 13:32, 22 February 2024 (UTC)