Talk:Asymptotic giant branch

message: This article would benefit from having more information about timescales. For instance, how long is the interval from RGB to AGB.129.21.55.82 (talk) 19:11, 30 January 2009 (UTC)
thread_title: Timescales

message: Probably meant to say "in radius", but the naïve might assume "in diameter."  This is vague at best and wrong at worst, since isn't even Sol expected to get bigger than 1AU radius in several billion years?  --Polymath69 13:33, 17 August 2007 (UTC)
replies: text: Nah.  Point break on Rocheworld.  Be there or B2 ;) Wnt (talk) 23:22, 6 July 2008 (UTC)
thread_title:  "as large as one astronomical unit" 

message: The diagram in this article shows stars moving horizontally from the main sequence to supergiant status.  The diagram shown in most of the other articles, e.g. giant star, shows the supergiants far higher in absolute magnitude. Please reconcile or clarify this. Wnt (talk) 05:21, 30 June 2008 (UTC)
replies: text: The supergiants are in roughly the same position in both diagrams.  In :Image:Stellar evolutionary tracks-en.svg, the luminosity of the 15 solar-mass track is shown as approximately 3·104 solar luminosities.  In :Image:HR-diag-no-text-2.svg, the absolute magnitude of luminosity class Ia is shown as around −7.  Since 4.83 − 5 log100 (3·104) = −6.36, you can see that the positioning is approximately the same. Spacepotato (talk) 17:37, 6 July 2008 (UTC)
replies: text: You're right - the distinction is actually that the stars starting these horizontal paths are 30,000 K or hotter class O stars, which are extremely rare.  The main sequence in the second link or at  stops at class B and doesn't include class O. Wnt (talk) 23:17, 6 July 2008 (UTC)

text: Hmm, thinking for a while about it: I think it's confusing that the image in Giant star and the image of this article regards different evolutional states of the stars. The image in this article draws a line along Zero Age Main Sequence, since the article is about star evolution; non-evolutionary HR-diagrams use to draw a line along main sequence which is some kind of mean evolutionary position. For most of the main seq the distance to ZAMS is small and constant, but becomes increasingly large for very massive stars, making ordinary HR-diagrams have kind of an upwards curve, which gives the impression of steeper increase of luminosity for "early" MS stars. Said: Rursus (☻) 14:16, 17 September 2008 (UTC)
thread_title:  Apparent contradiction 

message: I've just merged the stub article Asymptotic giant branch star into this article, and left a redirect there. Wdfarmer (talk) 09:23, 14 August 2008 (UTC)
thread_title:  Merge 

message: Text says:
:AGB CSE
I say: ATOTLAS! (All these obnoxious three letter abbreviation stinks). IAU should imitate the nomenclature style of IUPAC. Said: Rursus (☻) 13:26, 17 September 2008 (UTC)
thread_title:  Yech! 

message: In the "Circumstellar envelopes of AGB stars" section there is a calculation that starts from 10 km/s and ends in 1019 cm.  I see no reason to have the figure as 1019 cm rather than 1017 m, 1014 km or even 100 Pm (Peta-meters).  I would like to change this, but I don't know if there is some reason cm is used.  If anyone out there has an objection to changing it to 1017 m, especially someone with an astronomy background, please let me know.  Otherwise, I plan to change this before the month is out.
Lon of Oakdale (talk) 22:29, 3 October 2008 (UTC)
thread_title:  Circumstellar envelopes of AGB stars - units 

message: How does LAGB phase of Protoplanetary nebula relate to TP-AGB? Equal or LAGB later than TP-AGB? ... said: Rursus (bork²) 14:30, 9 January 2009 (UTC)
thread_title:  LAGB? 

message: Not sure if this is the right page for discussion, but this is one of only a couple pages that use the image http://en.wikipedia.org/wiki/File:Stellar_evolutionary_tracks-en.svg .  It only shows four tracks, which could be a LOT more informative--The tracks are all extremely different, and it's hard to tell what's going on in between them!  For example, what will become of a 5 Solar mass star?  Will a 1 Solar mass star make the same jog to the left as a 2 Solar mass star?  I've been building an understanding from this  page and its image, but that deals with stars entering the main sequence, not leaving it...  however, even a few more 'topographical' lines make it a lot clearer.
Can someone give an idea of where the lines for 30, 5 and 1 solar mass stars would go?  Even if you can't update the image, I would like to know what they would look like.  Thanks!  --Sowelu (talk) 09:55, 21 October 2009 (UTC)
thread_title:  Evolutionary track image 

message: Should this article mention how do asymptotic giant branch stars relate to S-type stars and carbon stars? Should this also discuss if every AGB star turns into S-type star and a carbon star before it turns into a preplanetary nebula? --Artman40 (talk) 05:21, 24 June 2014 (UTC)
replies: text: They're mentioned.  If you can add more information or explain it more clearly, then go ahead.  Note that there is a fairly lengthy article about Carbon Stars and a stub about S-type stars, so detailed information about these stars should probably go there, with this article restricted to describing how AGB stars are related to those and then linking.  Lithopsian (talk) 15:45, 24 June 2014 (UTC)
thread_title: S-stars and carbon stars

message: Substituted at 18:08, 17 July 2016 (UTC)
thread_title: Assessment comment

message: I've heard that the Sun will become larger on the Asymptotic Giant Branch than Its first red giant phase. Is this going to Happen?--THE COLOSSAL GALAXY NAMED IC1101 (talk) 06:50, 21 July 2020 (UTC)
replies: text: AGB stars are generally both more luminous and cooler than RGB stars, hence larger.  The sun is expected to become an AGB star at some point.  Many of the more popular writing about "the sun as a red giant" doesn't distinguish between the two stages and may well be referring to the AGB.  Read carefully between the lines, or refer to sources that actually distinguish the two phases.  Lithopsian (talk) 14:17, 21 July 2020 (UTC)
thread_title: During The Asymptotic Giant branch, Is the Sun larger than during its Previous red giant phase?

message: "The luminosity of the shell flash peaks at thousands of times the total luminosity of the star"
Instead of "total" would it be clearer to say "main branch" or "average"? Hcobb (talk) 16:36, 31 January 2021 (UTC)
replies: text: It is neither of those things.  Or both if you like, but hardly relevant.  What it is, and what it is trying to say, is that the flash "luminosity" is thousands of times greater than the electromagnetic radiation being emitted from the surface of the star at the time of the flash, or for that matter somewhat before or after it.  Luminosity is also a poor word since none of the energy is visible.  Lithopsian (talk) 16:53, 31 January 2021 (UTC)
thread_title:  The luminosity is thousands of times itself