Talk:Type II supernova

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Good article Type II supernova has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do. If it no longer meets these criteria, you can delist it, or ask for a reassessment.
An entry from this article appeared on Wikipedia's Main Page in the Did you know? column on May 6, 2007.
June 3, 2007 Good article nominee Listed
WikiProject Astronomy This article is within the scope of WikiProject Astronomy, which collaborates on articles related to astronomy.
Good article GA This article has been rated as GA-Class on the assessment scale.

This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.

Contents

[edit] Supernova article

The body of this article was formed from a section of the FA'd supernova page. The material was copied here primarily to reduce the length of the supernova article. This should allow for expansion of the content. — RJH (talk) 21:42, 1 May 2007 (UTC)

Nice work! ··coelacan 18:58, 6 May 2007 (UTC)

[edit] New article?

This article was just started? Nice work! Trevor GH5 21:28, 6 May 2007 (UTC)

I was "blown away" by this too ... seems it was split off from an existing FA, but it's still a great article. Kudos to those who wrote it! Antandrus (talk) 21:30, 6 May 2007 (UTC)

[edit] Good article nomination on hold

This article's Good Article promotion has been put on hold. During review, some issues were discovered that can be resolved without a major re-write. This is how the article, as of May 30, 2007, compares against the six good article criteria:

1. Well written?: This article fail to pass the well written criteria for good articles. But don't worry there is nothing groundbreaking in that article that can't be fixed, I allready fixed myself some of the litle.
First of all the Lead of the article, the guideline "In general, specialized terminology should be avoided in an introduction. Where uncommon terms are essential to describing the subject, they should be placed in context, briefly defined, and linked" is not met here "However the nuclear fusion of iron produces no net energy to sustain the star, so the core becomes an inert mass that is supported only by the degeneracy pressure of electrons." what does degeneracy pressure of electrons means ? You need to provide a short definition of degeneracy pressure. (the article linked is definitivly not a good article and provide a rather complicated definition).
I inserted a very, very simple explanation that is hopefully sufficient. (I didn't want to divert the lead into a full explanation, which would require one or more paragraphs.) — RJH (talk) 19:11, 31 May 2007 (UTC)
Now the main problem of the article, jargon, please read Wikipedia:Explain jargon "Type II-L supernovae show a linear decay of the light curve following the explosion, whereas Type II-P have a plateau in their light curve followed by a normal decay. Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium." do not meet it. "Linear decay" is jargon. "A plateau blablabla" could be perhaps rewritten as "conserve their luminosity then begin to lose light" or something like that much more understandable by a non expert in the subject. "Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium." I didn't understood that part... But perhaps it doesn't matter because it's not directly related to that article, doesn't it ? "Standard Model of particle physics" should be explained. "presence of hydrogen Balmer absorption lines in the spectra." what are those line ? "wave ionizes the hydrogen" what is ionization ? "(collapsars)" neologism ?
I've attempted to address your concerns. The word "collapsar" is being used in a significant number of scientific publications, so it's a a valid moniker. — RJH (talk) 15:34, 1 June 2007 (UTC)
2. Factually accurate?: Source checking in progress , Wikipedia:Avoid weasel words The interactions between neutrinos and the other particles in the supernova take place with the weak nuclear force which is believed to be well understood. However, the interactions between the protons and neutrons involve the strong nuclear force which is much less well understood." Who said that ? source it and perhaps delete believe and for strong nuclear say it is "not fully understood" or still unknown. Don't forget to provide some source for those fact.
I think this may belong under the "Quantum chromodynamics (QCD) in the non-perturbative regime" topic on the unsolved problems in physics page. The 2004 Nobel Prize page had a decent article on the Strong Force, so I linked that. (See the "A weaker coupling sets the particles free" section.) Hopefully that's satisfactory. — RJH (talk) 18:51, 30 May 2007 (UTC)
3. Broad in coverage?:
4. Neutral point of view?: What about the Flying Spagethi Monster and his noodly viewage ? (just kidding, )
5. Article stability?
6. Images?: Image:Evolved_star_fusion_shells.png The note in this picture seems to say that this picture is inacurate, someone should check it and eventually replace that picture if there is a problem. Also some graph for the different types of light curves may be usefull (a picture worth a thousands words).
Actually I think the illustration is correct. The (PDF) paper by Woosley et al on the evolution of massive stars shows Ne burning occurs before Oxygen fusion begins. I put a comment on the commons image talk page. There's already an image on light curves down in the "Light curves and unusual spectra" section. — RJH (talk) 15:08, 30 May 2007 (UTC)
- Esurnir 15:30, 30 May 2007 (UTC)

Please address these matters soon and then leave a note here showing how they have been resolved. After 48 hours the article should be reviewed again. If these issues are not addressed within 7 days, the article may be failed without further notice. Thank you for your work so far. — Esurnir 00:41, 30 May 2007 (UTC)

I agree with Esurnir's comments regarding the use of jargon. Some jargon maybe important for the article, but the density of jargon makes it difficult for a non-expert to follow. This reduces the effectiveness of what is otherwise a well-researched, well-illustrated article. --Volcanopele 22:28, 31 May 2007 (UTC)
Thanks for the feedback. I've tried to clear things up a bit. Please let me know if there are any more particular elements that need addressing. — RJH (talk) 15:34, 1 June 2007 (UTC)

[edit] Successful good article nomination

I am glad to say that this article which was nominated for good article status has succeeded. This is how the article, as of June 3, 2007, compares against the six good article criteria:

1. Well written?: All the potentially obscure jargon has been explained. In the future perhaps some edit could be usefull to "lighten" the lead" (it's just my point of view on the lead, but it pass WP:LEAD) the rest of the article is just great.
2. Factually accurate?: There is no problem everything is well sourced
3. Broad in coverage?: This article give all the important information on the matter, personnaly I found reading that article great for my knowledge (particulary the Core collapse section)
4. Neutral point of view?: No problem of point of view.
5. Article stability? It's stable, no edit war.
6. Images?: Picture are appropriate, all free license.

If you feel that this review is in error, feel free to take it to a GA review. Thank you to all of the editors who worked hard to bring it to this status. — Esurnir 19:44, 3 June 2007 (UTC)

Thank you. — RJH (talk) 14:47, 4 June 2007 (UTC)


[edit] How exactly degeneracy pressure fails?

Article says: "When the core's size exceeds the Chandrasekhar limit, degeneracy pressure can no longer support it, and catastrophic collapse ensues."

From my understanding, electron degeneracy pressure rises with density. New electrons crammed into each cubic meter get higher and higher speeds just because lower energy levels are all taken by electrons which were already there. This fails when new electron's energy is so high that it can fuse with proton (ordinarily it is not possible, e + p weigh less than n). Such electron "disappears", it no longer contributes to degeneracy pressure. Density starts to rise fast, more electrons fuse.

That's how degeneracy pressure fails. If this description is correct, can it be added to the article?—Preceding unsigned comment added by 89.102.207.196 (talk • contribs)

Well, first it would need a reference. I think it also needs some modifications to comply with the Wikipedia:MoS, such as avoiding unnecessary vagueness. But yes I think something like this would make a nice addition.—RJH (talk) 16:15, 12 May 2008 (UTC)