Talk:Star/Archive 3

Archive 1

Archive 2

Archive 3

"Atmosphere" correction

At the end of the "Main sequence" subsection, the word "atmospheres" incorrectly points to the term "Atmosphere (unit)" instead of the term "Stellar atmosphere". Please correct and then remove this comment. — Preceding unsigned comment added by 109.100.69.106 (talk) 18:22, 1 October 2012 (UTC)

Done. Thanks. —Alex (ASHill | talk | contribs) 00:54, 2 October 2012 (UTC)

Largest stellar mass

Sorry if I started this section incorrectly, I'm new at this, so feel free to move/fix/delete as needed.

Anyway, I found this at the end of the section on stellar mass: "However, a star named R136a1 in the RMC 136a star cluster has been measured at 265 solar masses, putting this limit into question."

I was reading somewhere recently that this actually presents a couple of possibilities--first that the Eddington Limit might need to be updated, and second that the star is actually two stars of much lower than Eddington Limit mass. I can't find the reference, so maybe that is not true, but I just thought I'd point it out.

Also, it seems to me that the Eddington Limit tells us that stars above a certain mass will be dominated by the radiation pressure vs the gravity holding them together, and thus will blow apart. Looking at the Wikipedia article on this star, it appears that it is doing exactly as predicted for a star above this limit, it is shedding mass very quickly. Doesn't this mean that the theory is supported, rather than the limit has come into question? I mean, just because a star is above the theoretical limit for the upper mass of stars (which is really just the limit to how big a star can be before radiative pressure starts shedding its mass), that doesn't mean the star can't exist, it just means that above that limit, if a star does exist, it will be very busy blowing its mass into space. Yes? No?

Perhaps a better wording would be to talk about how stars above this mass are rare because of the dominance of radiative pressure (they die very young), and that when a star above this mass is found (such as R136a1, with 265 solar masses) that star should be in the process of blowing itself apart from the moment it is born. Again, I'm not an expert or professional astronomer, and perhaps this is still too new to be considered 'fact,' but I love to point stuff like this out in case I can learn something from it.  :) Turboguppy (talk) 18:16, 23 September 2011 (UTC)

If I recall the issue correctly, I think the concern is not whether a cloud with that much mass can form and start to collapse into a protostar, but how does it become a main sequence star without blowing off the extra mass in the process? I know that one way to do it is to have a star with no metallicity, as is the case with the conjectured population III stars. The ESO article being used as the source suggests another method: the merger of two smaller, but still massive stars. You give the third option yourself: that it is actually a massive binary. As for the wording itself, well I guess that's just a common process in science; exceptions that test the consensus. Regards, RJH (talk) 19:19, 23 September 2011 (UTC)

Thanks, I think that clears up the confusion for me--it will be interesting to see what comes of it. Thanks! Turboguppy (talk) 03:09, 28 September 2011 (UTC)

Can stars have rings?

Are there any stars that have rings? YouthoNation (talk) 18:15, 30 September 2008 (UTC)

Yes: Debris disk—RJH

(talk) 19:09, 30 September 2008 (UTC)

Sort of, but only protostars or possibly brown dwarfs can have anything similar to a planet's ring. Skyintheeye (talk) 21:29, 9 February 2010 (UTC)

Samples of stars which have ring? Newone (talk) 03:03, 12 October 2010 (UTC)

Well, one might consider a debris disk a ring, albeit probably not as flat as Saturn's rings. There's also the protoplanetary disk, which is comparable.—RJH (talk) 14:53, 12 October 2010 (UTC)

The solar system is made out of the sun, and all of the debri around it. The debri around the star becomes planets and asteroids. So, in essence yes, a young solar system with a star in it has 'rings'. Karicats7 (talk) 21:01, 14 March 2012 (UTC) (talk)

I suggest the asteroid belt in our own solar system is a 'ring'. Jokem (talk) 21:09, 20 July 2012 (UTC)

Definition

"An astronomical object is defined as a star if it emits more heat, light and radiation than it absorbs." Does anyone know where this definition comes from and its vailidity? By this definition Jupiter, apparently, is a star, not a planet. __meco (talk) 10:24, 28 September 2011 (UTC)

This wording looks to be invalid and has some redundancy; both heat and light are radiation. I have no idea where it comes from. You could perhaps define a star in terms of whether it acquires sufficient mass to perform thermonuclear fusion of protons (not deuterium) to form helium at some point during its lifetime. But there are conjectured to be dark matter stars that could throw that definition out the window. Still, you'd need a definition that excludes deuterium-fusing brown dwarfs. Regards, RJH (talk) 16:16, 28 September 2011 (UTC)

I appreciate your take on it. It wasn't much of a reliable source, so I just figured I'd throw it out to see if anybody could somehow elaborate on it, which you did. __meco (talk) 08:22, 2 October 2011 (UTC)

Edit request from 94.66.78.71, 30 September 2011

Star, derives from a combination of Greek "αστήρ" (endless) with "άστερεον" (non-fixed) and "αστράπτον" (flashy)

94.66.78.71 (talk) 21:52, 30 September 2011 (UTC)

We'll need a reliable citation for this. It's only partly confirmed here:

Halsey, Charles Storrs (1882), An etymology of Latin and Greek, p. 80

The online etymology dictionary shows it as coming from aster, per the first above:

Harper, Douglas (2010), "star (n.)", Online Etymology Dictionary, retrieved 2011-09-30

Regards, RJH (talk) 21:54, 30 September 2011 (UTC)

Edit request from , 1 November 2011

{{edit semi-protected}} Please, change

Chugainov, P. F. (1971). "On the Cause of Periodic Light Variations of Some Red Dwarf Stars". Information Bulletin on Variable Stars 520: 1–3. Bibcode 1977A&A....61..809M to

Chugainov, P. F. (1971). "On the Cause of Periodic Light Variations of Some Red Dwarf Stars". Information Bulletin on Variable Stars 520: 1–3. Bibcode 1971IBVS..520....1C

because the Bibcode is wrong.

With best regards, Andras Holl (IBVS technical editor)

Andrasholl (talk) 10:22, 1 November 2011 (UTC)

Changed, thank you. Materialscientist (talk) 10:29, 1 November 2011 (UTC)

Dead links

So many wrong links! Newone (talk) 05:02, 11 April 2012 (UTC)

Fixed. This is quite "normal" for a large article which has not been overhauled for deadlinks for some time. Materialscientist (talk) 05:22, 11 April 2012 (UTC)

Red giant mass Discrepancy

Solar mass required for a star to become a Red giant according to various articles:

• Red Giant - 0.35
• Star - 0.4
• Stellar Evolution - 0.5

The same discrepancies can be found a mass limit for a star to fuse helium in various articles.

• Horizontal branch - 0.26 (presumably a mass for a star to become red giant)
• Star - 0.4 (not directly said)
• Helium flash - "about 0.5"
• Stellar Evolution - 0.5

--Artman40 (talk) 01:23, 17 June 2012 (UTC)

They should all probably be based on the lower bound for fusing helium, so around 0.5. (D'oh... I was mistaken. The lower bound would probably be a hydrogen-burning shell stage with an inert helium core, rather than helium fusing.) We need to find a definitive reference that will serve on all of the articles. Also, I'm not sure if there is significant variation caused by metallicity. Regards, RJH (talk) 22:42, 21 June 2012 (UTC)

These numbers largely reflect the uncertainty in this number; really, the text should reflect that uncertainty. It's unconstrained by observation anyway, since the age of a 0.5 solar mass star is longer than the current age of the Universe. —Alex (ASHill | talk | contribs) 23:13, 21 June 2012 (UTC)

If it is of any help, the following source estimates the lower limit at around 0.25, with stars needing 0.5 to reach the tip of the RGB:

Laughlin, Gregory; Bodenheimer, Peter; Adams, Fred C. (1997), "The End of the Main Sequence", Astrophysical Journal, 482: 420, Bibcode:1997ApJ...482..420L, doi:10.1086/304125. {{citation}}: Unknown parameter |month= ignored (help)

I'm not sure if there is a more definitive source available, but this seems pretty decent. Shrug. Regards, RJH (talk) 03:41, 22 June 2012 (UTC)

Thanks for the ref. There's a conference proceeding version that's a little easier to read: 2004RMxAC..22...46A. My summary for this purpose is that the maximum luminosity of stars increases for stars in the 0.16 to 0.25 solar mass range; there doesn't seem to be a sharp transition. All that said, there are no observable tests of this aspect of the model. I'll try to incorporate this into an article where appropriate, if someone doesn't beat me to it.

Re what determines the lower bound: it's the fully convective interior. Fully convective interior means no red giant phase (because convection mixes mass from through the star, so the star can fuse nearly all of the hydrogen in the star, not just the hydrogen in the core); radiative interior means red giant. I haven't (yet) looked at the articles to see if this is said well; if it isn't, it should be. —Alex (ASHill | talk | contribs) 10:01, 22 June 2012 (UTC)

Adams, F. C.; Graves, G. J. M.; Laughlin, G. (2004), García-Segura, G.; Tenorio-Tagle, G.; Franco, J.; Yorke, H. W. (eds.), "Gravitational Collapse: From Massive Stars to Planets. / First Astrophysics meeting of the Observatorio Astronomico Nacional. / A meeting to celebrate Peter Bodenheimer for his outstanding contributions to Astrophysics", Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias), 22: 46–49, Bibcode:2004RMxAC..22...46A. {{citation}}: |contribution= ignored (help); Unknown parameter |month= ignored (help)

Perhaps I'm mistaken, but I got the impression from the first article that stars with 0.25 solar masses may develop radiative core regions later in their lives, even though they are normally fully convective. (Perhaps from the higher abundance of helium?) Interesting if true. Regards, RJH (talk) 14:44, 22 June 2012 (UTC)

editrequest

After the phrase "putting this into question.[ref]" please add the following sentence into the same paragraph as its new last sentence:

A study have determined that stars larger than 150 solar masses in R136 were created through the collision and merger of massive stars in close binary systems, providing a way to sidestep the 150 solar mass limit.

-- 76.65.128.252 (talk) 07:48, 24 August 2012 (UTC)

Done. Thank you, RJH (talk) 14:20, 24 August 2012 (UTC)

References

References

Lead image

Which version? I prefer the larger version since it gives more context. If there is an awkward strip of text beneath one or the other when you see it in the article, that formatting is may due to the width of your browser window rather than being the "fault" of either image.

Smaller

Larger

Does anyone else have a preference? I prefer the larger version. Pine^✉ 07:40, 6 October 2012 (UTC)

I prefer the smaller one because the larger one seems a bit too tall, and ends up pushing the text into narrower area which doesn't look good to me, not to mention it does leave a strip of text underneath for most modern screen resolutions. If you could somehow find an intermediate between those two maybe that would be better. Cadiomals (talk) 14:28, 6 October 2012 (UTC)

Age Does Not Specify Type of Billion

The article notes the age of stars as "1 to 10 billion years", but does not specify if it is a US billion (thousand million) or a European billion (million million). As this is a significant difference, it would be very helpful if the article listed the age as a fully-written number in order to more clearly specify units. I'd edit it myself, but the citations don't seem to clarify, either. — Preceding unsigned comment added by 98.172.76.114 (talk) 00:22, 24 October 2012 (UTC)

Short scale (billion = 10⁹) is what was meant; the references in the academic literature mostly refer to Gyr, not "billion", so there's no ambiguity. Given that the English-speaking world now essentially uniformly uses the short scale, I don't think this is confusing in an English article, but I made that explicit the first time billion is used in this context in the article. —Alex (ASHill | talk | contribs) 02:45, 24 October 2012 (UTC)

Edit request on 29 October 2012

Please change "A star is a massive, luminous sphere of plasma held together by gravity" to "A star is thought to be a massive, luminous sphere of plasma held together by gravity.", in the first sentence, because it is an absolute statement. What we believe about the makeup of a star is still a theory given that no one has ever traveled to and taken a sample from one. Even when we are 99% sure of something, we always have to be careful not to make absolute statements.

Jpbstylist (talk) 22:58, 29 October 2012 (UTC)

Not done: please establish a consensus for this alteration before using the {{edit semi-protected}} template. - with changes like this, discussion would be better first. Mdann52 (talk) 13:26, 1 November 2012 (UTC)

Edit request on 2 December 2012

After the "Massive" section, I would like a section about hypergiants to be made. 35.11.55.167 (talk) 20:27, 2 December 2012 (UTC)

Not done: please be more specific about what needs to be changed. —Alex (ASHill | talk | contribs) 21:01, 2 December 2012 (UTC)

Spelling

Below the image of the constellation of Leo - "The constellation of Leo as it can be seen by the naked aye" - The naked aye? It should be "eye". 129.206.199.82 (talk) 18:14, 10 December 2012 (UTC)

You're right, of course, and I've fixed it. WilyD 18:49, 10 December 2012 (UTC)

Red dwarf age and accuracy

Claiming a ref is needed is not an excuse to re-insert incorrect and equally unsourced info into an article, claiming red dwarfs only last hundreds of billions of yrs was both incorrect and unsourced as well, read the red dwarf article! I have now given refs that 2 of the 3 closest stars to us have a lifespan of 4 and 8 trillion yrs and hope this will now allow the matter to lie. Thanks, ♫ SqueakBox talk contribs 01:03, 11 February 2013 (UTC)

The tens to hundreds of billions of years was better supported than tens of trillions by the ref that was there. The (better) ref you provided better supports your number; thanks. I expanded a bit and also made the statement more general, rather than using specific stars as examples. —Alex (ASHill | talk | contribs) 01:37, 11 February 2013 (UTC)

stars are "massive"?

article starts by "A star is a massive, luminous sphere". where luminous is objective, "massive" is only subjective. massive comparing to what? and why does it matter that it looks massive when compared to my daughter's ball and not to the black hole at the centre of most galaxies?!! 41.68.236.8 (talk) 13:27, 19 April 2013 (UTC)

"massive" is used 27 times in this article, in very few occasions it means anything at all i think. and please don't revert this last comment i am the same anon. user who posted this new section and i have no idea why you reverted my last edit!! 197.134.86.188 (talk) 17:00, 19 April 2013 (UTC)

I wonder if you are misunderstanding the word "massive". It is being used in sense 1 of the Wiktionary definition "Of or pertaining to a large mass", not the imprecise colloquial usage that you seem to assume. I agree that specifying a range of masses might make this usage clearer to non-scientists. Neither of your IP addresses has had any edits reverted. Dbfirs 22:10, 19 April 2013 (UTC)

The term "massive star" is not defined until late in the article. It should be done earlier (perhaps in the lede), and I'll try to find a way to do it. The term "massive" is also sometimes just used as an adjective (eg "stars less massive than 0.25 solar masses" or "one of the most massive stars known" and sometimes to refer to a class of stars (massive enough to go supernova -- the conventional definition). This latter class is finally defined at the end of Star#Mass, but was used many times before that.

An edit was reverted, presumably because it looked like an edit of someone else's comment due to the change in IP. —Alex (ASHill | talk | contribs) 22:58, 19 April 2013 (UTC)

Sorry, yes, I missed that revert. Changing IP addresses made the reverted edit look like vandalism by someone else. To avoid confusion, why not create an account? It would certainly improve the readability of the article to define "massive" earlier, even if it's just a footnote. Dbfirs 06:49, 20 April 2013 (UTC)

• lol @ user:Dbfirs, man, i'm not misunderstanding anything. it's you who don't get it yo! i explicitly explained: "large mass" compared to what? is the sun massive compared to other objects? sometimes, relatively, it depends compared to what! phew 197.134.147.164 (talk) 11:09, 15 May 2013 (UTC)

As I wrote above, it would certainly be better to define what astronomers mean by "massive". I agree that it can be vague adjective, though I think stars have a greater mass than most other objects in the universe. (We don't actually know how many black holes there are, but most of them are less massive than a star.) Apologies for doubting your level of education! I've made a link that should clarify what astronomers mean by "massive". Why not create an account to avoid confusion? Dbfirs 09:36, 19 May 2013 (UTC)

Edit Request June 20, 2013

In the Formation section the statement is made about a "terrestrial vacuum chamber". It is confusing, I think. It confused me, at least. Please change to "laboratory vacuum chamber". < My reasoning is that while you can have both industrial vacuums and laboratory vacuums, there are no vacuum chambers that are nonterrestrial, so using the term "terrestrial" contains no information in this context. (Although I suppose some of our satellites and possibly Martian probes might have vacuum chambers, IDK, virtually nobody will be aware of that minutia, so the qualification is useless in this context) >. Thanks for the consideration! Two other things I noticed: 1) The introduction 'defines' a star as a massive ball of plasma but you have to really dig into the article to find out that that means masses of at least 85-90 times the mass of Jupiter. I think that it would be helpful to put that in the introduction explicitly (and also how many Earth masses that is) and 2) In the photograph comparing the size of the terrestrial planets with gas giants and gas giants with stars, I had to look at the second panel for some time to distinguish Earth in the second panel. For some reason Neptune is colored blue in that panel. Adding "Earth is small black sphere on far left in the 2nd panel" would be helpful. 216.96.76.236 (talk) 21:32, 20 June 2013 (UTC)

Oldest star?

The oldest star said here is HE 1523-0901. However, HD 140283 is considerably older. Can I move it here? ==Johndric Valdez (talk) 09:17, 2 February 2014 (UTC)==

Stellar distance

At the moment, it is written in the main text:

"The first direct measurement of the distance to a star (61 Cygni at 11.4 light-years) was made in 1838 by Friedrich Bessel using the parallax technique. Parallax measurements demonstrated the vast separation of the stars in the heavens.[23] Observation of double stars gained increasing importance during the 19th century. In 1834, Friedrich Bessel observed changes in the proper motion of the star Sirius, and inferred a hidden companion. Edward Pickering discovered the first spectroscopic binary in 1899 when he observed the periodic splitting of the spectral lines of the star Mizar in a 104-day period. Detailed observations of many binary star systems were collected by astronomers such as William Struve and S. W. Burnham, allowing the masses of stars to be determined from computation of the orbital elements."

There are two problems in this paragraph.

First, Bessel was not the fist to directly measure the distance to a star. Specially when putting in this way: "first direct measurement of the distance to a star". Struve even published his results about the distance of Vega before Bessel did. Yes, in the discussions at the articles about Struve, Bessel, Vega and stellar distances, it has been claimed that "authoritative sources say that...". What (science) historians do say? Citations to original papers will be needed!

Second, there is written "William Struve", while actually his name was Friedrich Georg Wilhelm von Struve (link points to correct article and the name _inside_ the link has correct name). Just a 'typo', but should be corrected for sure. — Preceding unsigned comment added by Tonisee (talk • contribs) 12:30, 17 July 2014 (UTC)

Getting to this late, but better late than never I suppose. I have removed the piping on Struve's name. I'll try to look into the priority for stellar parallax. I expect it is a very murky issue, however, and I'm not hopeful of finding a clear answer. A2soup (talk) 03:16, 18 January 2017 (UTC)

Fastest star fleeing

http://news.sciencemag.org/space/2015/03/fastest-unbound-star-flee-our-galaxy
--YeOldeGentleman (talk) 00:28, 7 March 2015 (UTC)

Fate of low-mass stars

In a recent edit, Lithopsian changed the item on low-mass stars to suggest that they never become white dwarfs, but simply exhaust their hydrogen and begin to cool. The Stellar evolution article, however, states that these stars do eventually evolve directly into white dwarfs. Obviously, this is a theoretical matter since no one has observed (or even could have observed) a low-mass star that has exhausted its hydrogen, but the two articles should be consistent and both reflect scientific consensus. This is not something I know much about, so I was wondering if anyone could throw light on the matter? Is one of the articles wrong? Is there significant debate in the scientific community, which could perhaps be noted in the text, with both theories described? A2soup (talk) 08:04, 21 June 2015 (UTC)

The cited source says that low-mass stars become helium white dwarfs. The main point of Lithopsian's change was that they never become red giants of any flavor, which is supported by the source. I will make this correction; thanks for pointing it out. —Alex (Ashill | talk | contribs) 08:50, 21 June 2015 (UTC)

Yes, hard to encapsulate all the subtleties in one bullet-point. I think it is better now. I've tweaked a couple of wikilinks and straightened out two references with the same name. I don't think there is significant debate except perhaps on minor detail. You could quibble about whether the final stage of the lowest mass red dwarfs deserve to be called white dwarfs when they are hardly hot enough to be called yellow, but they are a degenerate ball of helium so no big deal. It is possible that there is a short period of thin hydrogen shell burning that could significantly affect the final temperature before fusion gives out, but again it is just a detail. A more important clarification might be to make it obvious that these theoretical helium white dwarfs are not the helium white dwarfs that we have actually observed. Those come from binary interactions.

The stellar evolution article jars a bit with this one in other ways, classifying things into different groups with different names. I should probably straighten them out to match although it is all a bit arbitrary and not even all researchers use the same names. The dividing lines between the masses could also be a bit confusing. For example, within this single article the limit for very low mass stars is set at 0.25, 0.4, and 0.5 without much clarification on why the differences. All can be considered correct, for different initial conditions and slightly different models, but more consistency would be less confusing. Lithopsian (talk) 11:55, 21 June 2015 (UTC)

proton-proton chain reaction

In the 41H → 22H + 2e+ + 2νe reaction, the energy release is given as (4.0 MeV + 1.0 MeV) which is not consistent with the Wiki page on the proton-proton chain reaction (which assigns 0.4 MeV to the same process). Is there any chance someone could fix this? I suspect that 0.4 MeV is correct but not sure.128.240.12.1 (talk) 18:36, 6 August 2015 (UTC)

I've fixed that reaction, but the whole thing probably needs citing better. Lithopsian (talk) 20:58, 6 August 2015 (UTC)

visibility of stars outside the milky way

the article's teaser seems to imply that some stars *outside* the milky way are visible from earth, which i understood as being with the naked eye, but after some research of my own (https://answers.yahoo.com/question/index?qid=20070619192110AAkkCVp) and a little bit of thinking about the scale of things, makes no sense at all: all the stars we see with the naked eye are from within the milky way of course. Shouldn't we correct the summary to make that clearer? In general, having a section that would clear up how many stars are visible (see To do) and where they generally are located would be useful. There's some information about that in List_of_brightest_stars, but it would be useful to have a summary in here... --TheAnarcat (talk) 03:36, 8 September 2015 (UTC)

I agree about the lead being misleading, so I took out the part about the Milky Way. I didn't say that all visible stars were in the Milky Way, because that would also be misleading in a different way since there are telescopes and such. A2soup (talk) 04:22, 8 September 2015 (UTC)

Poorly defined brown dwarfs?

A star runs proton fusion continuously, a planet has never run any fusion process. Brown dwarf have deuterium or/and lithium fusion for a short time upon formation. Nothing poor about that! --129.13.72.196 (talk) 09:26, 9 September 2015 (UTC)

That's not a universally accepted definition. Also, there is no sharp division between deuterium burning or not at the lower mass end. Some objects burn just a little deuterium, some more. There are also definitions involving a mass range or formation scenarios. Gap9551 (talk) 19:24, 24 November 2015 (UTC)

Linkrot

For entirely unrelated reasons I've just had occasion to go through this article clicking on every single external link (i.e. non-internal, not just the stuff in the similarly named section). It is a… depressing exercise. I would encourage regular editors on this article to do the same, and fix the various links that are plain dead, 404, point to a domain squatting service, etc. I'd offer to help but I have a few too many maintenance tasks on my plate as it is (one of which lead me to this drive-by visit) and I have absolutely zero relevant domain knowledge. Sorry. --Xover (talk) 13:41, 23 November 2015 (UTC)

Simply tagging the dead links would have been an almost-no-effort exercise, far more helpful than just pointing out that "everything is broke". Lithopsian (talk) 13:55, 23 November 2015 (UTC)

My apologies if I came across as "everything is broke". What I intended to convey was simply the factual statement that I had observed a number of external links in the article that were no longer functioning in various ways and that the number was not an insignificant one. I realise it would make the job for the regular editors easier if I were to tag each link, but regret that I simply do not have the capacity right now. I'm working from a list of broken links captured on the incoming side of an external website; so I'm looking for (often) a single broken link in an article that has hundreds of them, and in a list of about 750 articles (so we're talking several thousand links). Again, my apologies. --Xover (talk) 13:29, 24 November 2015 (UTC)

binary evolution

I added a bit on binaries to the section on stellar evolution. I left this section pretty vague, so if anyone would like to add more detail, I think it would be worthwhile. OtterAM (talk) 22:53, 17 December 2015 (UTC)

Help

What are the importances of star? Ishanbull (talk) 14:00, 24 February 2016 (UTC)

Temperature of core of the sun.

The temperature of the core of the sun is widely stated to be 15 million kelvins, not 10 million as stated in the "Nuclear Fusion Reaction Pathways" section. On that note, the correct terminology is "kelvins" (plural), not "kelvin" (singular), unless the temperature is only one kelvin. Kelvins are quantitative, not degrees on a scale. At least I try (talk) 08:42, 25 May 2016 (UTC)

The "solar core" does not have a single temperature. Unless you just want to pick the temperature of the single point at the centre of the star. The fusing region of the sun extends to about 20-25% of its radius and the temperature varies from around 15 million K (actually closer to 16 million) at the centre to below 10 million at the outer edge. The 15 million number is widely quoted as "the core temperature", but (approximately) 10 million may be a more appropriate single number for characterising fusion across the whole core. Lithopsian (talk) 11:10, 25 May 2016 (UTC)

Semi-protected edit request on 27 August 2016

In paragraph 3, the sentence "When the hydrogen fuel at the core is exhausted, a star of mass 0.4 times greater than the Sun's[2] will expand to become a red giant." would be significantly more intelligible if it read: " When the hydrogen fuel at the core is exhausted, a star of mass greater than 0.4 times the Sun's mass[2] will expand to become a red giant."

66.222.227.129 (talk) 22:43, 27 August 2016 (UTC)

 Done Isambard Kingdom (talk) 22:48, 27 August 2016 (UTC)

Historical meaning of "star"

Reading and musing about the Death Star, I suddenly began to wonder: why is it called a "star"? It's neither bright, nor point-like, nor even large enough to be a planet – it has none of the properties associated with stars, or even planets, except that it floats in space, too. However, in light of the historical division into fixed stars – stars in the astronomical sense, essentially – and wandering stars, plus shooting stars, it occurred me that the original historical meaning of star corresponds to that of "(simple) celestial body", and could cover anything from luminous stars, planets, moons (the Sun, Moon and comets used to be counted among the planets in the early modern period), minor planets and comets to meteors, and echoes of this original broad definition are still extant in popular usage and culture. There's also the concept of the "dark star", which seems to have originally referred to an outdated scientific theory, but entered popular consciousness as a metaphor and became widespread although nobody seems to know what a dark star might be in the literal sense. (In contemporary German, Gestirn – also compare Wandelgestirn – preserves this wide meaning, remaining as a separate, if somewhat dated term besides Stern.) Maybe this is worth including in the article as a historical note. --Florian Blaschke (talk) 15:55, 3 October 2016 (UTC)

If you can find reliable sources discussing these concepts then you can write a new section. Otherwise it is WP:OR and you'll need to wait until after your paper on the subject is accepted for publication ;) Lithopsian (talk) 15:58, 3 October 2016 (UTC)

Alternatively, it could also be included in Wiktionary. --Florian Blaschke (talk) 16:05, 3 October 2016 (UTC)

No, the relationship between "star" and "astronomical object" should be stated in the first few sentences of this article, but my edits are brutally reverted. UU (talk) 03:54, 30 December 2017 (UTC)

Your revision was incorrect because the initial change you made happens to match an H II region. Please read Wikipedia:Civility and tone down your attitude. Thank you. Praemonitus (talk) 18:56, 31 December 2017 (UTC)

Semi-protected edit request on 6 March 2017

Under Formation and evolution: Main sequence section change 'The Sun's is expected to live 10 billion (10^10) years.' to 'The Sun is expected to live 10 billion (10^10) years.' 142.73.82.13 (talk) 22:22, 6 March 2017 (UTC)

Thanks for spotting that. Edit done. Lithopsian (talk) 22:36, 6 March 2017 (UTC)

Distributions

I've been lookin' in Wikipedia for information about the distribution of sizes of stars, and I can't find anything except a statement in Sun that the sun is bigger than some percentage of stars. Could someone add some information like this? There are several distributions that could be mentioned: mass, absolute magnitude, spectral class, mass-to-light ratio... Eric Kvaalen (talk) 17:00, 18 March 2017 (UTC)

The initial mass function varies depending on what population you're studying, so you can't really give a simple table of data. Praemonitus (talk) 02:15, 19 March 2017 (UTC)

@Praemonitus:: Well yes, one can give data for the whole Milky Way, or for our neighborhood. I can actually get a rough idea by looking at the List of nearest stars, but I'm sure there are better sources! Eric Kvaalen (talk) 07:17, 19 March 2017 (UTC)

@Eric Kvaalen:: Okay, but now you're talking about properties of a region (solar neighborhood or Milky Way) rather than an object (star). I don't disagree that it would be interesting data, but perhaps this isn't the right place for it? Praemonitus (talk) 16:16, 19 March 2017 (UTC)

@Praemonitus:: We could start an article called something like Stellar size distribution, and link to it in this article. But we need some content! By the way, I see that in the Initial mass function article there's a link to Luminosity function, which can be for galaxies or for stars. For instance, there's a White dwarf luminosity function. They don't seem to worry about what part of the galaxy is being considered. Eric Kvaalen (talk) 05:16, 20 March 2017 (UTC)

Semi-protected edit request on 31 March 2017

Under the section Formation and Evolution, a bullet point reads: Intermediate-mass stars, between 1.8–2.5 M☉ and 5–10 M☉, pass through evolutionary stages similar to low mass stars, but after a relatively short period on the RGB.... The acronym RGB as meaning Red Giant Branch is not stated anywhere in the document. Please can this be added. Many thanks, Jonathan. 86.179.18.222 (talk) 16:12, 31 March 2017 (UTC)

Thank you for spotting that. I'm not particularly fond of TLAs, even when they are explained somewhere, so I've changed "RGB" to "red giant". I hope this is OK. Dbfirs 18:30, 31 March 2017 (UTC)

I changed it back. RGB is not an synonym (or acronym) for red giant. I expanded the term and linked it to the appropriate article. No more TLA, at least not in that paragraph. Possibly more work is needed to clarify just why red giants are not only found on the red giant branch. Lithopsian (talk) 19:16, 31 March 2017 (UTC)

Thanks for linking. I should have checked if we had an article. I'm still not clear what was wrong with my edit, except that not all red giants are in what is now called the RGB, but I'll trust your expertise. As far as I can see, RGB stars are just a specific type of red giants. Dbfirs 20:23, 31 March 2017 (UTC)

You pretty much got it. Red giants are any relatively cool inflated star (short of being a supergiant), but the red giant branch (RGB) is a specific evolutionary stage named for its position in the H-R diagram. Red giants may also be found in other parts of the H-R diagram such as the asymptotic giant branch (AGB) and red clump (not really a TLA for that). RGB stars are hydrogen-shell burners with an inert, and sometimes degenerate, helium core. Lithopsian (talk) 20:51, 31 March 2017 (UTC)

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Grammar

In the second paragraph, "The total mass of a star is the determines its evolution and eventual fate."

I believe "is the" should be removed. — Preceding unsigned comment added by Meters (talk • contribs) 20:37, 16 November 2016 (UTC)

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Star

The sun is an average signed yellow star.It is about 10 ill ion kilometers wide and about 4.5 billion years old.Below is a list of different types of star supergiant,dwarfstar,netron star,black holes,blue-white star,Average-sized star and other. Group in ICT (talk) 02:58, 29 June 2017 (UTC)

Post-Main Sequence section

I'm trying to brush up on my astronomy and am surprised that the "Post-main sequence" main-article reference is to Red Giant. The text also implies the next stage post-main sequence is a red giant, and in trying to follow it I felt I was misdirected. Other Wikipedia articles state there's a subgiant phase that comes first, and for solar mass stars it will last considerably longer than the star's time as a red giant (2.6 billion years as opposed to 130 million years burning helium - numbers from Subgiant and Main Sequence pages). Nor is a red giant the end of the process either. Not for any mass of star. So why is the reader being pushed toward red giants? I would have found it more helpful if the featured main-article reference for this section was Stellar Evolution.

I'd also liked to have seen

• a sub-header for the initial part of the section, something like "Small and medium mass stars" to parallel the "Massive stars" sub-section that follows it.
• a clear statement that a star is called a red giant during separate potentially-disconnected stages: red giant branch, red clump and AGB phases.
• more clarity about when the star enters the red giant branch phase. I feel the lumping together of hydrogen shell burning, core collapse and helium burning in the first paragraph obscures what happens when.
• better agreement between this page and others as to time to go before the Sun starts helium burning. For example here it's 5 billion years and on the Main sequence page it's 6.5 billion. There's also little clarity about whether these are main sequence times or main-sequence plus subgiant times.

A table of timescales that stars are expected to spend in all evolutionary phases for a few sample masses of stars would be awesome, similar to the one on the subgiant page but including later phases. Either here or on the Stellar Evolution page.

Jonh333 (talk) 16:22, 10 July 2017 (UTC)

I've added links to some more informative pages. Despite being a featured article, this one is pretty light in that area. Of course stellar evolution is the best starting point for learning about ... well, stellar evolution. Lithopsian (talk) 19:30, 10 July 2017 (UTC)

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how many stars are there?

2 — Preceding unsigned comment added by The lord 66 (talk • contribs) 16:36, 1 February 2018 (UTC)

The exact number is not known, of course, but if you read the article, it says that the number in the observable universe could be as many as 3 × 10²³, that's three hundred thousand million million million. Dbfirs 17:36, 1 February 2018 (UTC)

Semi-protected edit request on 5 June 2018

Good morning Wikipedia team!, In order to add more accurate historical reference details to the start public article, could you please help add the Maya culture Astronomical observation facts reference information to the "Observation history" section of the "Star" article ASAP

Reference information dates to America, pre-hispanic observations made by the Mayan culture, construction of astronomical observatories, and the creation of numerous complex calendars dated around 2000 years B.C.

Reference useful information gathered from the main "Maya Wikipedia article" that I could gather is the following:

The Maya made meticulous observations of celestial bodies, patiently recording astronomical data on the movements of the sun, moon, Venus, and the stars. This information was used for divination, so Maya astronomy was essentially for astrological purposes.

https://en.wikipedia.org/wiki/Maya_civilization#Astronomy https://en.wikipedia.org/wiki/Maya_astronomy#Astronomical_Observations

Thank you ! Renato Muro (talk) 19:57, 5 June 2018 (UTC)

I would recommend taking a look at History_of_astronomy#Mesoamerica and see if you can enhance that content. The history section on this page is just a high-level overview. Thank you. Praemonitus (talk) 20:21, 5 June 2018 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Sam Sailor 16:17, 6 June 2018 (UTC)

A Commons file used on this page has been nominated for deletion

The following Wikimedia Commons file used on this page has been nominated for deletion:

• Comparison of planets and stars (2017 update).png

Participate in the deletion discussion at the nomination page. Community Tech bot (talk) 07:51, 28 June 2018 (UTC)

I've replaced the image in the article. Praemonitus (talk) 16:44, 28 June 2018 (UTC)

Stars

The opening paragraph should say how many stars there are in the observable universe.--Wyn.junior (talk) 16:58, 4 February 2019 (UTC)

Resolved

 – Added an estimate to an existing sentence. Praemonitus (talk) 01:32, 5 February 2019 (UTC)

Paragraph "Collapse"

In "Collapse" you write of stars of "less than 1.4 M☉" (said to become white dwarves) and "more than 1.4" (said to become neutron stars). What about precisely 1.4 solar masses? Adjust it correctly please! 212.186.0.174 (talk) 08:20, 14 July 2019 (UTC)

Most sources say "about" or "roughly" 1.4, so I changed it accordingly. A strong magnetic field or rapid rotation can allow a higher mass white dwarf, for a time. I think a full explanation would add a lot of low-level detail that isn't needed for a summary of this type. Praemonitus (talk) 22:55, 23 January 2020 (UTC)