Talk:Supernova

First sentence

"A supernova is a rare astronomical event that occurs during the last stellar evolutionary stages of a massive star's life...": this definition might be suitable for type II SNe but definitely not for type Ia. Ia progenitors are still unknown (plural is used on purpose). This is misleading and should be reworked.

Indeed the progenitor systems of type Ia SNe are still debated. It is known however, that they involve a white dwarf – and so are not the death of a massive star. So this sentence was just plain wrong. Tried to fix it. 134.160.214.17 (talk) 08:53, 6 June 2018 (UTC)

Isn't there a place where 'astro-people' can go to discuss stars in scientific terms? An encyclopedia isn't meant to be a graduate level textbook on the subject. Rather, it should be a place where common people can go to quickly find out what something is. Simple, in lay terms. I am SO disappointed in what WP has become over the last 10 years. It has morphed into a place where subject-matter "experts" can spew out technobabble and fight over competing "theories", while the rest of us intellectually inferior types can merely look on and try to comprehend what all the fuss is about. Being an engineer myself, I view this is as a form of snobbery that one might expect to find in academia, but not in a public encyclopedia. Why must editors continually over-complicate definitions and throw around terminology that you KNOW the average person doesn't understand? As it stands, one would have to be an expert on stellar physics to even read this article, much less use it for anything. And that means, in very simple terms, that it is USELESS to the vast majority of readers who find it. Again, I repeat... Useless to the average reader. Even when I wrote for NASA as a systems architect, I was told to keep it at a 9th grade level. Because not everyone is a specialist on everything. Think about that before continuing with your edits, please. Reserve those discussions for publications or academic frat meetings - and leave the rest of us out of it. Finally, please note that there is such a thing as "good enough" for general use. Not every topic needs to be perpetually beaten to death in the vain search of perfect accuracy. Perfection is the enemy of Done. Right? 98.194.39.86 (talk) 21:58, 9 June 2018 (UTC)

Pronunciation

As far as I've seen, there is no WP standard that says an article must insert a flow-disrupting pronunciation guide in the first sentence of an article. Hence I moved it down following the definition and turned it into a more complete sentence. If there is a concern with this change, please clarify. Thank you.—RJH (talk) 19:22, 2 May 2011 (UTC)

I've erased "pron" from the first formula so that it'd look more text-like. All the options preserved. Josh, linguist (talk) 11:39, 19 March 2013 (UTC)

Furthermore I doubt that two native German-speaking scientists who coin a Latin neologism would at the same time not hesitate to introduce a new official Latin pronunciation which, I have to state it, sounds pretty English. — Preceding unsigned comment added by 217.6.16.93 (talk) 08:53, 9 January 2015 (UTC)

New candidate supernova class

See:

• Cartwright, Jon (June 8, 2011). "Brightest supernovae are in a class of their own". Nature News. doi:10.1038/news.2011.354. Retrieved 2011-06-08.
• Quimby, R. M. (June 8, 2011). "Hydrogen-poor superluminous stellar explosions". Nature. doi:10.1038/nature10095. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

Regards, RJH (talk) 17:24, 8 June 2011 (UTC)

Close supernova

I just read about a supernova that is supposed to happen very soon, that is extremely close to earth. A more proficient editor than me should add it. Here's the article. http://science.cabot.ac.uk/index.php/2011/10/a-star-set-to-blow/

75.92.160.60 (talk) 21:27, 2 October 2011 (UTC)

It would be more appropriate for History of supernova observation. This is an article about supernovae in general. Regards, RJH (talk) 19:20, 4 October 2011 (UTC)

Newer Supernova Than stated in this article has now been confirmed.

G1.9+0.3 Has been confirmed as the youngest supernova within the Milky Way galaxy. ref. http://news.nationalgeographic.com/news/2008/05/080514-supernova_2.html

To summarize:

Supernova G1.9+0.3 discovered by Stephen Reynolds and his team at North Carolina State University has been confirmed as the youngest supernova discovered to date, it is estimated at only 140 years old and located within the constellation of Sagittarius. Although obscured by interstellar mass at the time of it's explosion recent studies of it have shown it to be a rapidly expanding and very young supernova, currently the youngest confirmed by astronomers. — Preceding unsigned comment added by 184.59.144.219 (talk) 04:09, 11 February 2012 (UTC)

Is it true? Drajaytripathi (talk) 04:58, 13 June 2015 (UTC)

Yes this is true PugLover.2016 (talk) 07:01, 10 July 2016 (UTC)

Date of the word supernova

The introduction says that "supernova" was first used in print in 1926 (according to Merriam-Webster). Under "Discovery" it says that it was first used in a lecture in 1931 and at a meeting of the APS in 1933. In the article about Fritz Zwicky it says that the word was coined by him and Walter Baade in 1934.

In Fritz Zwicky: Novae Become Supernovae by T Koenig (http://articles.adsabs.harvard.edu//full/2005ASPC..342...53K/0000058.000.html) it says that Zwicky and Baade had been using the term since 1931 and that the first publication in print was by Knut Lundmark in 1933 (article dated Dec 31 1932).

Zwicky writes himself in Types of novae (http://authors.library.caltech.edu/4785/1/ZWIrmp40.pdf footnote on page 85): Baade and I first introduced the term "supernovae" in seminars and in a lecture course on astrophysics at the California Institute of Technology in 1931.

This source seems to sum it up pretty well:

Osterbrock, D. E. (2001), "Who Really Coined the Word Supernova? Who First Predicted Neutron Stars?", Bulletin of the American Astronomical Society, 33: 1330, Bibcode:2001AAS...199.1501O {{citation}}: Unknown parameter |month= ignored (help)

Regards, RJH (talk) 22:51, 25 February 2012 (UTC)

But "The word supernova was coined by Swiss astrophysicist and astronomer Fritz Zwicky, and was first used in print in 1926", as it says in the introduction, is contradictory to that it was first used by Zwicky in 1931 and also to that it was first used in print in 1933. And 1934 as given in in the article on Fritz Zwicky is also contradictory. — Preceding unsigned comment added by 83.254.200.12 (talk) 09:01, 26 February 2012 (UTC)

Yes, I agree. The introduction, and its corresponding source, would appear to be in error. We should use the Osterbrock (2001) source for consistency. Regards, RJH (talk) 20:19, 28 February 2012 (UTC)

like to raise two points which I think should be corrected within the article.

First, the introductory chapter contains lots of stuff that simply isn't relevant to someone trying to find out what a supernova is, at the surface level. True, what I tried to do with my edits was to shorten it, because I have a problem with overly long intros. And I know that brevity is formally very much not a criterion for the intro, as a matter of written policy.

But still, relevance to a first time learner I believe is. From that viewpoint I would think what has to be told is a) it's an unusually and suddenly luminous star, b) long after we saw them the first time, we learned that there are many different kinds of them, c) one or two representative examples of the thing, and d) the fact that they are believed to be caused by different modes of runaway fusion. That's it; I believe the rest of the details should be pushed down into the body of the article, because before you can understand the differences, you need a huge lot of preliminary text to understand it, which can only fit the body format.

The lead is written according to the guidelines in WP:LEAD in that it is intended as a summary of the primary points of the article. It is three paragraphs long, which is less than the maximum for a long article like this. I found your edits to the lead to be heavy handed and overly extensive. It has been thoroughly reviewed by many editors (hence the FA rating), and thus I believe it is just fine for the purposes of this encyclopedia. Please keep in mind that your concern about the supposed excess length is one opinion among many; other reviewers find brief leads to be equally objectionable. I'd like to keep it in balance with the prevailing standards and past consensus. Regards, RJH (talk) 18:25, 20 June 2012 (UTC)

That is then why I brought my concerns onto the talk page. I'm arguing for a particular stylistic choice, which we evidently do not agree about. Both those choices fall within the guidelines and you've already reverted my idea. Thus, I'm seeking further output and consensus before touching the article further. Decoy (talk) 22:59, 20 June 2012 (UTC)

The second part is that, right now, the physical theory concerning supernovas is interspersed widely within the article, as is the astronomical data we have of them. Your mileage may vary, but I think those aspects should be separated and concentrated into their own sections, so as to make for tighter presentation, which can then also be more easily found from the topmost content listing. Especially since I think people simply interested in the night sky and the ones interested in stellar dynamics are two different crowds, with two different needs. As such, I'd advocate a wholesale content-retaining reorganization at the level of single claims. That is not as big or difficult as it sounds, but it might seriously help a total newcomer internalize the contents better, while not taking away anything from the expert.

The physical models for supernova are contained in the "Current models" section, so I find your statement puzzling. Note that the lead should be redundant with elements of the article body, which is why we don't need to relocate content from the lead into the article. To me the article flow is logical and I'll object to a wholesale rewrite without a solid plan and a wider consensus. Perhaps you could clarify your perspective with some specific examples? Regards, RJH (talk) 18:30, 20 June 2012 (UTC)

I mostly agree. But I think the redundancy in the introductory section should be minimal, and that it should only mention, not explain or reason with, what is contained in the body. I agree that my edit was heavy handed, and I'm happy that you reverted it. But I also believe something even better could be found between the basic idea of what is now in there and what I tried to put there.

Two particular examples wrt the intro chapter would be the precise velocity estimate of what supernovas put out, and the mention of shockwaves in the interstellar medium. They are sequelae of the process, not defining factors of what a supernova really is. In fact, they vary widely depending on what the local matter density actually is and how the supernova happens to come into being. What is left of it as well; all of that is, I think, better handled in the body of the article, by moving the relevant content there. Decoy (talk) 22:59, 20 June 2012 (UTC)

Finally, don't get me wrong. The article is exceptionally good as it stands, as evidenced by its featured status. It's just that I think it could be even better. Right now I'd say its structure is at the level of a rather good encyclopedia article. But it ain't yet a Feynmann lecture, where every question is answered precisely when you were about to ask it in the logical procession of things, if you know what I mean. Decoy (talk) 18:06, 20 June 2012 (UTC)

This is an encyclopedic article, so it should most definitely not be turned into a Feynmann lecture. (Yes I have read Feynmann.) If you want to build an in depth presentation, I strongly urge you to try the Wikiversity or Wikibooks projects; those have very different goals than a straight-forward encyclopedic presentation of the facts. Regards, RJH (talk) 18:30, 20 June 2012 (UTC)

I agree that the summary paragraph needs work. It can't be a coincidence that this reverted edit was almost identical to one I tried to make a few weeks back. The summary may only be three paragraphs, but one of those paragraphs (the only one that really has a problem) is overly long and not at all a concise summary of any portion of the rest of the article. Some of it is simply incorrect. My response to these problems was just to remove three quarters of that paragraph, but perhaps it could be written in a better way. Lithopsian (talk) 20:10, 20 June 2012 (UTC)

The concern I had with Lithopsian's modification to the lead is that it just moved a chunk of text down into the article; that should not be happening because the lead should be a summary of the article. It sounds like we need to start by reaching a consensus on how to write the lead. The consensus rule of thumb on the lead is to have at least one sentence per article section, and to mention the major points in the presentation.

As it happens, the large paragraph in question was previously two separate paragraphs; somebody came along and combined them. (Compare, for example, to the version at the FA promotion.) This sort of trivial modification happens frequently on Wikipedia and it isn't always beneficial. It should be easy enough to split it again. However, I can guarantee you that whatever we come up with will not remain intact over time. All we can do is try to maintain it in a somewhat recognizable form. Regards, RJH (talk) 21:16, 20 June 2012 (UTC)

What I mean by my reference to the Feynman Lectures is not about their content, but their explanatory style and well-structured flow of thought. They go to extraordinary lengths in teaching stuff in an order that is understandable, easily memorable, and logic-wise coherent. I believe such a style of presentation is a merit to an encyclopedia article as well, even if it's patently clear that these two genres are very separate an sich.

So, I mostly agree. But I wouldn't call reorganization which leaves the content intact, while aiming to improve its flow at the same time, trivial. Nor would I stop text movement which aims to achieve those goals. I did my changes precisely because I care about that sort of stuff quite a lot. I don't dispute your viewpoint about my heavy-handedness or the one about my lack of proper grammar, since I'm not a native speaker of English myself. But at the same time, I do think I have a point to make about the flow of thought. Perhaps *especially* because I'm what they call an "avid amateur", so that I can look at the article from a learner's point of view. Decoy (talk) 22:59, 20 June 2012 (UTC)

I've edited that second paragraph in the summary. I've removed or reword things that are inaccurate. It is considerably shorter but at least not misleading now. I think it is a good length and says what needs to be said? Lithopsian (talk) 22:47, 21 June 2012 (UTC)

I'm basically done with the structural changes and edits, mostly to the sections on classification and models. These should now be consistent with current research. I'm still waiting on feedback about merging the type II and type Ib/c articles into a single core collapse article, and possibly much of the core collapse section could then go there, leaving just a summary in this article because it is quite long right now with a lot of detail. Lithopsian (talk) 17:58, 24 June 2012 (UTC)

Neon over oxygen?

In the diagram http://en.wikipedia.org/wiki/File:Evolved_star_fusion_shells.svg, it shows the shell of neon (atomic number 10) above oxygen (atomic number 8). It this correct? http://en.wikipedia.org/wiki/White_dwarf#Stars_with_low_to_medium_mass states that "If the mass of a main-sequence star is between approximately 0.5 and 8 solar masses, its core will become sufficiently hot to fuse helium into carbon and oxygen via the triple-alpha process, but it will never become sufficiently hot to fuse carbon into neon." So in this star, why would Neon-20 float above Oxygen-16?

As I am not an astrophysicist and lack the skills to modify that diagram anyway, I thought I would start this discussion. If I am wrong, it would be nice if this good article explained why the neon shell would be above the oxygen. 71.22.115.39 (talk) 16:15, 25 November 2012 (UTC)OxyB4Neon

The image is hopelessly naive and over-simplified. Still, for what its worth, Neon starts burning at a lower temperature, and therefore before, Oxygen, and any Neon shell will be found below the Carbon shell and above the Oxygen shells. So the image should be considered correct. Lithopsian (talk) 18:13, 25 November 2012 (UTC)

So, I guess the triple-alpha process only produces some oxygen and is overshadowed by a later process after neon burning. Okay, then why would the oxygen not bubble above the neon, given it's lighter atomic weight?

Also, looking at http://en.wikipedia.org/wiki/Alpha_process, it shows that you cannot get neon with oxygen as a precursor. What am I missing? oh. I found it, at http://en.wikipedia.org/wiki/Carbon-burning_process. It seems that carbon-burning results in sodium, magnesium, oxygen as well as neon. Still, this only occurs in stars great then 8 solar mass so I am at a loss as to why the oxygen does not float above the neon.71.22.115.39 (talk) 20:37, 2 December 2012 (UTC) OxyB4Neon

Nothing to do with "floating". This is burning. Neon burns first. The diagram indicates the location of shell burning, not the location of actual elements. Various elements occur mixed all over the place, especially Magnesium, Oxygen, and Neon which are all produced together from Carbon. Lithopsian (talk) 20:43, 2 December 2012 (UTC)

Classification

Should this be mentioned?

Types of Supernovae

Type Ia. These result from some binary star systems...

Type II. These supernovae occur at the end of a massive star's lifetime...

However, these types of supernovae were originally classified based on the existence of hydrogen spectral lines: Type Ia spectra do not show hydrogen lines, while Type II spectra do. ... However, if the original star was so massive that its strong stellar wind had already blown off the hydrogen from its atmosphere by the time of the explosion, then it too will not show hydrogen spectral lines. These supernovae are often called Type Ib supernovae, despite really being part of the Type II class of supernovae. Looking at this discrepancy between our modern classification, which is based on a true difference in how supernovae explode, and the historical classification, which is based on early observations, one can see how classifications in science can change over time as we better understand the natural world.

(Those were quotations.) Josh, linguist (talk) 12:01, 19 March 2013 (UTC)

It is mentioned, in great detail. Possibly too much detail. Read the sections on supernova models. It could be more succinct in this top level article, which might be easier to follow, but until the detail articles are rationalised I don't want to delegate all the detail. Lithopsian (talk) 12:39, 19 March 2013 (UTC)

First, I think it still should be mentioned somehow in the "lede" of the pertaining section. That the "taxonomy" doesn't represent primary differences in general.
Second. You say the article should be liter or what? Then I suggest if we draw not that (or another) formal classification first, but give a trivial "taxonomy" on the matter — types (or 'kinds') of supernovae - depending on the processes involved. THEN it's followed by the table with that formal classification. What do you think?
AN IDEA! What about preceding the "Classification" section by that new one to depict those major types of blow-ups I meant? For example, we could depict the few different known types of environment producing SNe. If that is described in the following "Current models" section, I mean, for an amateur reader (especially when s/he goes into this for the first time or so), some rough phenomenon adumbration may come first. You may say the overall idea might already be gained in the article's lede, but I think, if the lede is delivering the "main overall" — i.e. what t.f. it is (the matter leaps out due to the pressure of either sort), the suggested "distinguishing" section could roughly describe the needed circumstances in the least formal way. Or, either way, we could shift the existent sections — with making some ordering corrections.
PS. As for that "detailedness" of this article you mentioned above, I saw some score of rather much more "abundant-in" ones, now in comparison, this one looks not at all very monstrous for me:) Josh, linguist (talk) 15:04, 21 March 2013 (UTC)

The lead does mention the two types, but I feel it is rather lost in the second paragraph. Have to be careful messing with the lead on a featured article but it could probably be improved. Lithopsian (talk) 22:26, 21 March 2013 (UTC)

New Type of Supernova

I think this should be also mentiond: Harvard press release: new kind of supernova. But my english is not so good. Can someone ad this? Catadupa (talk) 09:24, 27 March 2013 (UTC)

It doesn't seem major.  ? Josh, linguist (talk) 13:09, 27 March 2013 (UTC)

It isn't major, but it still deserves a mention. Probably in the type Ia detail article. I thought it might already be there, but a quick look doesn't show anything. If nothing else, it is interesting because it blurs the line between the non-destructive novae and supernovae which completely destroy the star. Lithopsian (talk) 13:51, 27 March 2013 (UTC)

Here are articles I found about it:

• Foley,, Ryan J. (10 Dec 2012). "Type Iax Supernovae: A New Class of Stellar Explosion". arXiv:1212.2209. {{cite arXiv}}: Cite has empty unknown parameter: |accessdate= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: date and year (link) CS1 maint: extra punctuation (link)
• Wang, Bo (6 Jan 2013). "Double-detonation explosions as progenitors of type Iax supernovae". arXiv:1301.1047. {{cite arXiv}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: date and year (link)

I hope they help. --Richard-of-Earth (talk) 19:14, 28 March 2013 (UTC)

They look same...
To pile it out, Astronomers have discovered a new miniature version of a supernova. Josh, linguist (talk) 12:41, 2 April 2013 (UTC)

The links above are wrong, but there really are two papers. They are both referenced in the article already. We should avoid using press releases and other web pages as references when the real deal is available. Lithopsian (talk) 14:57, 2 April 2013 (UTC)

Fixed the link of Double-detonation explosions as progenitors of type Iax supernovae. As for the abstract summary, it says suggested class name of "type Iax supernovae" (SNe Iax). But the paper is 2013. Not sure it the name is accepted in 2014. Thanks, Marasama (talk) 09:50, 10 August 2014 (UTC)

Nomenclature

Article should clarify whether the "SN[YEAR] XX" naming system would apply to Milky Way objects - I don't think that it does. Presumably we would have (for example) "Supernova Sagittarii 2013", with GCVS name assigned shortly thereafter (e.g. "V5991 Sagittarii"), as opposed to (e.g.) "SN 2013mb", if a Milky Way supernova were discovered in modern times. — Preceding unsigned comment added by 184.47.125.210 (talk) 19:00, 22 August 2013 (UTC)

Asymmetry section

I do not understand the first sentence in that section and I think that probably a word is missing.--Jrm2007 (talk) 23:45, 1 November 2013 (UTC)

4 diagrams (could be useful)

(with google translator help) Hallo, I did this job for Italian Graphic Lab, I've also prepared an english version of them, if somebody wants to take a look at them... in the future they could become useful somewere. File:Supernovae as initial mass-metallicity.svg File:Remnants of single massive stars.svg File:Collapsar as initial mass-metallicity.svg File:Jet supernovae as initial mass-metallicity.svg -- Fulvio ³¹⁴ 10:52, 28 November 2013 (UTC)

SuperNova Dust

A news item about dust produced by a supernova, for the authors if they think the information is valuable.Jcardazzi (talk) 16:22, 20 March 2015 (UTC)jcardazzi http://news.cornell.edu/stories/2015/03/milky-ways-center-unveils-supernova-dust-factory

Consideration

"A supernova is a rare astronomical event that occurs during the last stellar evolutionary stages of a massive star's life..."

Wait a minute, how about type Ia supernovae? They are different. SkyFlubbler ^(talk) 14:14, 18 January 2016 (UTC)

Actually, the white dwarf in SNIa is in the last stellar evolutionary stages of a massive star's life. As the white dwarf is near 1.4 solar masses, its progenitor must have been about 6 to 8 solar masses. The progenitor has mostly ended its life. Technical not perhaps "massive", but as an introductory sentence, and is often stated similarly elsewhere in astronomical sources. I.e. Jacquiline Mitton in "The Penguin Dictionary of Astronomy" says "A supernova explosion occurs when an evolved massive star has exhausted its nuclear fuel." The text following the first statement is formally explained anyway. Arianewiki1 (talk) 10:21, 19 January 2016 (UTC)

Introductory sentence

"A supernova is an astronomical event that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion."

Modifications to this sentence is quite difficult, mostly because the causes of the event and also the remnants are diverse.

It address the truth that:

1) Destruction of a white dwarf or massive/supermassive star are at the end of the life of the star.

2) The final event occurs very quickly. I.e. Massive stars less than a second or white dwarf where the collapsing shockwave is slightly faster c.0.4 seconds.

3) It is catastrophic because it destroys the star

4) The energy created is titanic

5) The supernova remnant appear as an explosion.

Saying "A supernova is an astronomical event that occurs at the end of the life of certain stars, when they are completely destroyed in a catastrophic explosion." is incorrect.

1) Only massive stars can go supernovae. Those that are white dwarfs near the Chandrasaker limit are close to 1.4 Solar masses, but the original progenitor was massive star.

2) Supernovae can produce neutron stars / pulsars, hence such stars are not necessarily completely destroyed.

(This is all explained in Paragraph 5)

The introductory sentence is supposed to accurately reflect the definition of a supernova. The structure as it exists precisely does this, and considers the diversity of different types of supernova.

Moreover, Lithopsian statement to change this by saying "Replace factually incorrect lead sentence (see talk page))" is already incorrect, just by ignoring neutron/pulsar are generated by supernova.

Also changing edits by saying " (Remove fluff sentence originating from non-neutral editor (User:WAFred))" and "remove a rather speculative section apparently written by an involved party", is plainly provocative and ignores WP:GF. If you have proof or evidence of a "non-neutral editor" or "an involved party", it should appear on this talkpage. Who is the involved party? Seemingly claiming some unknown 'User:WAFred' (who doesn't exist) as justification is plainly unacceptable. Arianewiki1 (talk) 18:40, 12 April 2016 (UTC)

NOTE: Re-reading the complaint that "Remove fluff sentence originating from non-neutral editor (User:WAFred))" assigned to this edit in question can be construed as a derogatory comment under WP:PA. Editors should not avoid WP:CIV. Also making ANY kind of disparaging remarks about other editors without proof with no justification or reason is clearly unacceptable. Arianewiki1 (talk) 19:10, 12 April 2016 (UTC)

Type II energy output

Why does one table say type II produces 1 foe but another table says 100 foe? Asgrrr (talk) 20:25, 21 May 2016 (UTC)

Nevermind, first is without neutrino energy, right? Asgrrr (talk) 20:27, 21 May 2016 (UTC)

capital T required by Type Ia supernovae ?

In the article, both "Type Ia" and "type Ia" are found within sentences. — Preceding unsigned comment added by 217.186.217.219 (talk) 21:22, 13 June 2016 (UTC)

Type Ia is correct. Thanks for the heads-up! Arianewiki1 (talk) 03:11, 14 June 2016 (UTC)

Chinese and arab texts

Only the Chinese text is specific. The Arab text is not agreed upon, as is clearly mentioned in the cited article. Furthermore the article cited is not a primary source, as it is simply restating one possibility from someone who helped them. This error should be addressed.

We can be certain of the Chinese example, but the Arab example is dubious at best, and calling it "islamic" is also incorrect. — Preceding unsigned comment added by 180.54.78.138 (talk) 20:17, 30 November 2016 (UTC)

Introduction Explanation (again)

@Patrug: "A supernova is an astronomical event that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion."

Modifications to this sentence is quite difficult, mostly because the causes of the event and also the remnants are diverse.

It address the truth that:

1) Destruction of a white dwarf or massive/supermassive star are at the end of the life of the star.

2) The final event occurs very quickly. I.e. Massive stars less than a second or white dwarf where the collapsing shockwave is slightly faster c.0.4 seconds.

3) It is catastrophic because it destroys the star

4) The energy created is titanic

5) The supernova remnant appear as an explosion.

Also noted

1) Only massive stars can go supernovae. Those that are white dwarfs near the Chandrasaker limit are close to 1.4 Solar masses, but the original progenitor was massive star.

2) Supernovae can produce neutron stars / pulsars, hence such stars are not necessarily completely destroyed.

(This is all explained in Paragraph 5)

Actually too, the white dwarf in SNIa is in the last stellar evolutionary stages of a massive star's life. As the white dwarf is near 1.4 solar masses, its progenitor must have been about 6 to 8 solar masses. The progenitor has mostly ended its life. Technical not perhaps "massive", but as an introductory sentence, and is often stated similarly elsewhere in astronomical sources. I.e. Jacqueline Mitton in "The Penguin Dictionary of Astronomy" says "A supernova explosion occurs when an evolved massive star has exhausted its nuclear fuel." The text following the first statement is formally later explained anyway.

Sentence 2

"This causes the sudden appearance of a "new" bright star, before slowly fading from sight over several weeks or months."

After describing what a SNe the text describes what they observationally appear like. They appear suddenly in a few days, but can fade from view quickly or slowly depending on their distance and type.

If you add that they explode in a few seconds (which varying anyway depending on the scenerio), then you also need to explain how and why, which just confuses readers. Sure the true star collapse is fast, but visually is rises between half-a-day and several days. In truth it explains in general terms what is view when a SN explodes.

Also the Introduction is a base summary, and summaries what SNe in the least amount of words. (Considering the history of this page, the first paragraph has always been modified, and to avoid unnecessary changes.) Much time was spent formulating this paragraph and IMO you'll need to explain any modifications.

As for "...important pre-decay time-scales", means exactly what here? Important to whom? (It is discussed later anyway.) Is a supernova when the star collapses or when the expanding shell becomes bright enough to be able to see it, which is near its maximum light? (Former takes seconds, the latter takes days. Word "suddenly" is a compromise that covers all.)

If you wish to change this, you must discuss this here, and also gain consensus to do so.

Q. The real question are these statements factual? Thanks. 14:05, 2 February 2017 (UTC)

SN 2013fs (PTF13dqy) early observation

Can an editor knowledgeable about astronomy take a look at SN 2013fs (PTF13dqy). Given the early observation data of this event SN 2013fs might deserve a chapter in this article or even a page. My knowledge of astronomy is a bit rusty, and never was that good. I have referenced my recent changes and also found more information here.[1]

It is better suited for Type II supernova article. Ruslik_Zero 20:51, 15 February 2017 (UTC)

I'd say even better-suited for its own article. A single supernova is unlikely to change what needs to be said in a catch-all article except as a passing mention. The authors of papers about that supernova (or others) inevitably think it changes the world, but only time will tell if that is true. See WP:TOOSOON. Lithopsian (talk) 22:18, 15 February 2017 (UTC)

It looks like someone created an article at 09:28, 15 February 2017. SN 2013fs

147.148.251.204 (talk) 00:20, 16 February 2017 (UTC)

Novae and Supernova

This article says in the Introduction: "Supernovae are more energetic than novae. In Latin, nova means "new", referring astronomically to what appears to be a temporary new bright star. Adding the prefix "super-" distinguishes supernovae from ordinary novae, which are far less luminous. The word supernova was coined by Walter Baade and Fritz Zwicky in 1931."

However, Elenceq want to changed this, by removing everything but the first line to a new section on "Etymology."[2]

The original should stay as written because it explains, qualifies and reinforces the differences between novae and supernovae, and the link to novae. The introduction ought to summarise the main document, which is further explained under section Discovery Secondly, this text stablises the article from contentious edits, where some confusion has occurred or was expressed in the past betwee novae and supernnovae.

I see not need to change this at all. Seeking consensus to agree. Arianewiki1 23:11, 28 September 2017 (UTC)

There should be an "Etymology" section - because many readers like myself want to know the ORIGIN of the term. Knowing the genesis of a term or name is important to some of us, and this is common practice throughout Wikipedia. Why not explain where and how the term / name originated??? 98.194.39.86 (talk) 22:04, 9 June 2018 (UTC)

Hmmmm - it might be a gravitational lens or?

A gravitational lens has the same effekt to an observer not able to resolve objects with less than one arcsecond distance like all abservers without telescope. I think many supernovae in the past might well be gravitational lenses. 84.118.82.226 (talk) 14:01, 2 February 2018 (UTC)

No. Not possible. It doesn't work that way. Arianewiki1 (talk) 01:15, 3 February 2018 (UTC)

Hmmmmm - why not? — Preceding unsigned comment added by 84.118.82.226 (talk) 12:08, 3 February 2018 (UTC)

Gravitational lenses don't "focus" properly. They produce lines, arcs, or multiple images, not a single brighter point-like image. There are examples of gravitational lenses of supernovae, but they are easily recognised for what they are. Start reading here for fun, and here to really learn how it works. Lithopsian (talk) 20:16, 3 February 2018 (UTC)

Not nova

As above (at First sentence, and Introduction Explanation (again) and probably more), I’d really like a “9th grade level” definition of nova, supernova, and hypernova.

Alternatively; how do you ask a question like;

“What is it called when a dying star [... or what?] explodes”

so that the answer is only one of nova, supernova, or hypernova.

MBG02 (talk) 04:10, 30 November 2018 (UTC)

Nova means new. It was given to what people thought were 'new' stars, because they never saw them before. But the real cause isn't that the star is new, it's that an existing star increased in brightness for some reason, and became visible. What exactly to call an dying star that explodes depends on what kind of star it was, and why it exploded, but most of those things will be novas of some kind. I hope that helps. Headbomb {t · c · p · b} 22:23, 30 November 2018 (UTC)

Initial Paragraph

I've just restored the first paragraph back to the original accepted version. The need is due to likely missed vandalism by Tsalina308 on 28 September 2018 here[3]. here[4] and here[5]. They've only made three edits[6] This was again changed by an IP 204.48.98.237 here[7] on 23 October 2018, and has survived to now.

There should not be any controversy in reverting the series of edits. Arianewiki1 (talk) 04:17, 29 May 2019 (UTC)

The "bulk" of all elements?

In the body of the article [8] it is said that supernovae are a "major source of elements heavier than nitrogen". That has been my understanding. But with this edit: [9] Arianewiki1 restored the following sentence into the lede:

"Supernovae create, fuse and eject the bulk of the chemical elements produced by nucleosynthesis."

Is this true? No qualification is given for elements heavier than nitrogen, so one can interpret Arianewiki1's sentence as meaning that the bulk of all elements are the product of supernovae. A further concern is the word "bulk". What is meant by this? The number of atoms produced by nucleosynthesis or their total mass? Anyway, I think Arianewiki1's sentence either needs to be fixed or removed. Thank you. Attic Salt (talk) 13:09, 13 June 2019 (UTC)

The statement isn't entirely correct, for a few reasons. One reason is that alpha elements are created by fusion inside of massive stars but then ejected by supernova explosions, so it's not correct to say that the supernovae "create" or "fuse" those particular elements. On the other hand, iron peak elements are largely produced and ejected in Type Ia supernova explosions. So the situation is different for different groups of elements, and for different types of supernovae, and requires a somewhat more lengthy explanation. Aldebarium (talk) 19:43, 13 June 2019 (UTC)

Thanks. I was under the impression that most of the helium, lithium, etc. up to something like iron (this article says it is nitrogen) are produced by nucleosynthesis inside of stars, not in supernovae, hence my concern about the sentence quoted above. Attic Salt (talk) 19:55, 13 June 2019 (UTC)

The revert was likely vandalism by an IP, because they state: "Deleting statements that attribute bulk of nucleosynthesis to supernovae as this is now thought to primarily take place through neutron star collisions". This just isn't true. The rest of Attic Salt's assertions are not true, as I neither support nor condone the statement. e,g. It is not Arianewiki1 sentence. The edit with 2 cites was added by WAFred in November 2015 here[10], actually. Reading Supernova nucleosynthesis perhaps might help you, where it says: "...suggesting that the expected shock-wave nucleosynthesis is an essential component of supernova nucleosynthesis."

The reference source is "Galactic Chemical Evolution: Hydrogen through Zinc" [11][12] tends to support the statement. Boron to nitrogen is generate during the life of the star by nucleosynthesis as these elements appear is SN spectra. They are also generated in the shockwave, except for perhaps Lithium or Beryllium, which maybe formed via Spallation#Nuclear spallation. (Attic Salt: Again. If you don't understand something, then leave it alone. Also Wikipedia is not an educational resource.)

Blaming me for what others write is deplorable, especially without even bothering to look for any evidence to say something is true. Again Attic Salt, you've been repeatably told to stop targeting me, and leave me and my edits alone. Do so. Utter rudeness will be the next step. OK. Arianewiki1 (talk) 00:19, 14 June 2019 (UTC)

Attic Salt. Any thoughts of a retraction of these false accusations? Arianewiki1 (talk) 22:58, 14 June 2019 (UTC)

Attic Salt. Any thoughts of a retraction of these false accusations? Arianewiki1 (talk) 22:49, 16 June 2019 (UTC)

Note: the previous revision changed my text above (I assume inadvertently); I just reverted it back to what I wrote earlier today. Aldebarium (talk) 01:11, 14 June 2019 (UTC)

I did that as a honest mistake. Sorry. Arianewiki1 (talk) 03:23, 14 June 2019 (UTC)

No problem. In any case, I'll try to think about how to expand that statement about nucleosynthesis into something that's more generally applicable to different element groups and different types of supernovae, while still keeping it brief enough to be in the lead section- it's probably a bit of a challenge to find the right balance. Aldebarium (talk) 10:21, 14 June 2019 (UTC)

One possible point of confusion, I've been assuming that supernova nucleosynthesis refers specifically to nucleosynthesis occurring during the supernova phase of stellar evolution. While stellar nucleosynthesis refers to nucleosynthesis in stars, even those that might go supernova, but before the supernova phase. Comments? Attic Salt (talk) 14:53, 16 June 2019 (UTC)

Also note that this source: [13], makes it clear that supernova nucleosynthesis only contributes the "bulk of the heavy elements (A ≳ 20) observed in nature", very different from the unqualified statement given in the lede that "supernovae create, fuse and eject the bulk of the chemical elements produced by nucleosynthesis." Hence, my concern. Attic Salt (talk) 15:04, 16 June 2019 (UTC)

I've added this source to the article, and used a more accurate sentence already given in the body of the article. Attic Salt (talk) 15:28, 16 June 2019 (UTC)

Please stop editing this page. There is enough supposition above that shows little understand of the subject at hand. The core collapse and bounce make the heavier elements, the shockwave makes the lighter elements undergo nucleosynthesis. The only difference between supernova ejection and stellar superwinds is only in the ejected nebula's composition and their abundances.

This edit[14] based on what being said is unfounded and likely OR or possibly added disruptively. e.g. The references do not mention nitrogen in the context presented. The first reference doesn't even mention nitrogen! (I gave you the link explaining it, but do this?) I do think they might have meant the carbon-oxygen-nitrogen cycle, but the sources don't say that ether. Another option is after they read about the effects on Earth for a neaby SN event and the creation of nitrous oxide: but that isn't in any related given reference. I removed the nitrogen that later appears in the text too, and replaced it with an uncontroversial option that is true. Arianewiki1 (talk) 08:05, 17 June 2019 (UTC)

I'd like to make a suggestion that I hope will be helpful for this discussion. There is an exceptionally clear and well written review article on the topic of stellar and supernova nucleosynthesis and the origin of the elements that was published in Science (journal) a few months ago. It is up to date and explains all of these issues very well, and it would be very valuable as a reference for the Supernova article. I would highly recommend that anyone interested in pursuing this discussion further should read this article as it will go a long way toward clarifying which elements are formed through which processes and in what kinds of objects or events. Unfortunately the article is behind the AAAS paywall, but if you have access or can get a hold of the article, this will be very useful, and I hope that it may be helpful in reaching consensus as to what should be stated in the Supernova article. Here is the link to the Science article. (DOI: 10.1126/science.aau9540) Aldebarium (talk) 15:13, 17 June 2019 (UTC)

Stellar nucleosynthesis vs supernova nucleosynthesis

As I understand it, supernova nucleosynthesis refers specifically to nucleosynthesis occurring during the supernova phase of stellar evolution. While stellar nucleosynthesis refers to nucleosynthesis in stars, even in massive stars before they enter the supernova phase. This interpretation of terminology is borne out in reading the article by Jennifer Johnson (Science Magazine, already cited in Supernova). See, for example, bottom of page 2 of her article, where she says: "... supernovae enrich the Universe in three ways. First, they eject the products of nucleosynthesis built up over the star’s lifetime. Most carbon, oxygen, and magnesium, for example, are made before the core collapse, and the explosion simply distributes these elements into space. Second, the extreme temperatures and densities caused by the shock wave drive additional nucleosynthesis. In particular, the iron ejected by core-collapse supernovae comes not from the core but from explosive burning of material in the silicon shell during the supernova. Last, the additional shocks that occur as the ejected material plows into surrounding ambient gas accelerates some particles to close to the speed of light, making cosmic rays."

In light of this, then, I think we need to be careful with sentences like "Supernovae are the major source of elements heavier than nitrogen." or "Supernovae create, fuse and eject the bulk of the chemical elements produced by nucleosynthesis." The supernovae phase of stellar evolution does, yes, disperse elements inside of a star, but the production of many of those elements is not (apparently) what we would call "supernova nucleosynthesis" -- it is "stellar nucleosynthesis". In that regard, I note that Johnson is very careful with her words. The periodic table shown in her Figure 1 is labeled as "Nucleosynthetic sources of elements in the Solar System." That is, after supernova dispersal. So, labels on individual elements as coming from "exploding massive stars" includes those created both by pre-supernova steallar nucleosynthesis and, also, supernova nucleosynthesis.

Attic Salt (talk) 13:07, 21 June 2019 (UTC)

"Exploding white dwarfs" are supernovae too. We, and the article, tends to forget them, but they actually contribute more of the iron-peak elements than do core collapse supernovae. Another thing to remember is that models of supernovae aren't actually very good at reproducing the proportions of heavy elements that we observe, so we should take it all with a pinch of salt. Another point we could perhaps make clearer (or just leave for supernova nucleosynthesis?) is the absolute and relative yields of many of these elements. For example, core collapse supernovae eject a lot of carbon - more than any other element except hydrogen, helium, usually oxygen, and sometimes neon - partly because the outer layers of the progenitors are carbon-rich and readily ejected. However, AGB stars produce even more carbon, so supernovae are responsible for only a minority of the carbon in the universe. Likewise, the vast bulk of material ejected by a core collapse supernova is hydrogen and helium, the hydrogen unprocessed material from the big bang and the helium partially from the big bang and partially from fusion, but minuscule quantities compared to overall levels present throughout the universe ever since the big bang. On the other hand type Ia supernovae produce very little hydrogen or helium. Lithopsian (talk) 20:20, 21 June 2019 (UTC)

Attic Salt. Hands in the air. Reading the response above confirms why you should not be editing this article. Saying "Stars that eventually explode as supernovae are a major source of elements heavier than nitrogen in the interstellar medium…" other than the appalling sentence structure, it is mostly wrong. e,g, The definition of a exploding star is a supernova. So just say supernova. Saying: "a major source of elements heavier than nitrogen", but the article (and cite) says: "Stars that eventually explode as supernovae are a major source of elements from oxygen through to at least rubidium." "nitrogen" "above nitrogen" is a fiction that you have made up as original research. (Worst this has the same point has been made by Lithopsian, but you won't listen. I agree with the summary of Lithopsian above, and suggest the a note might be added to the article might help. After reading this, you also now do not have consensus at all.)

The Introduction is meant to be a summary of the article Lead, and because of the complexity of the subject, the text has to be a general compromise. You don't seem to care about that, and are just 'digging in the heels' to be difficult as possible. It is called sanction gaming, and is against policy. Arianewiki1 (talk) 01:25, 22 June 2019 (UTC)

I changed "stars that eventually explode as supernovae" to "supernovae", but added "in the interstellar medium" since some elements are created before the supernova phase. I think this accommodates both Lithopsian's point and Arianewiki1's unhappiness with the sentence's clunkiness. I ask Arianewiki1 to consider the quote from Johnson, given above, in which it is explained that supernovae disperse elements created in the star prior to exploding. The issue of "major source of elements from oxygen through to at least rubidium" can be seen in the periodic table in the article and is Figure 1 in Johnson. Thanks, Attic Salt (talk) 12:49, 22 June 2019 (UTC)

By the way, I didn't make up any fiction about nitrogen. That was there (in the body of the article) before I started editing this page. Still, I don't see anything wrong with it. Nitrogen is one atomic number below oxygen, and the periodic table in the article makes it pretty clear that supernovae contribute lots of elemental abundance above nitrogen. I honestly don't see why this is controversial. Thanks, Attic Salt (talk) 18:41, 22 June 2019 (UTC)

This a joke response, right? The statement "I honestly don't see why this is controversial." Could it possibly be because it is just wrong?

Let's see. You did these reverts[15], [16], [17], claiming some source which does not say what you claim, but still say: "I didn't make up any fiction about nitrogen. That was there (in the body of the article) before I started editing this page. Still, I don't see anything wrong with it. Nitrogen is one atomic number below oxygen, and the periodic table in the article makes it pretty clear that supernovae contribute lots of elemental abundance above nitrogen." You've been asked where it says in the article "about nitrogen" or "nitrogen" appears in the article. (It doesn't, does it?) Evidence says you've added this on a total fiction[18], especially because the two linked sourced don't say this and Johnston article wasn't then linked. (The Francois (2004) cite in the article didn't even mention Nitrogen (except by stellar winds for ¹⁴N).

The likely reason why this was added was because of the abstract statement "We computed the evolution of the abundances of O, Mg, Si, Ca, K, Ti, Sc, Ni, Mn, Co, Fe and Zn in the Milky Way." This was the part of their study, but it does not say that other supernova abundances exist. But you then added another Truran (1977) reference to try and justify the change.[19] After Lithopsian's disruptive edit here[20] and adding the Johnson cite here[21]. Looking at the new image of the Periodic Table, you followed this with`this edit.[22]. saying: "The Johnson article makes it clear that this should be qualified as "about nitrogen" given her Figure 1."(yet you say above that "") THE QUOTE DOES NOT SAY WHAT YOU CLAIM, and worst "the quote from Johnson" doesn't appear in that article at all. Yet you still defend it!

Evidence suggest you are pushing a POV and manufacturing stuff up to hold onto the your 'wrong' opinion. Evidence says this is original research. What stinks is that on top of this, you accuse me of : "...so one can interpret Arianewiki1's sentence as meaning..." "Anyway, I think Arianewiki1's sentence either needs to be fixed or removed" (Worst you refuse to retract the false accusation.) I never added this statement (it was WAFred) I reverted the edit because the reasoning by the IP 69.229.4.161 was incorrect.

But the final insult was these five successive edits[23] adding cites that don't even say what you claim.

You have been advised of what the central problem is with the current text by Aldebarium here [24], [25] to generalise and/or improve the statement. But that doesn't matter either.

But even if this is acceptable, it is clear that you targeted this part of this only only because of my revert of an IP edit, and you thought it was a chance "to nail me" on some esoteric point just to frustrate the editing process. You were pushed on by Lithopsian pointy edits here[26] and here[27], especially when they claim "…and of course complete rubbish." (Then to make sure of this, they then delete the cites, making certain the burn their bridges behind them[28] on a unrelated pretext.)

This kind of tactical behaviour is not the only time (over several ANIs now).

Even when pointed out about sanction gaming, the latest series of edits and above continue this same kind of gaming. We have now reached the stage of getting an ANI requesting a topic ban. Arianewiki1 (talk) 03:06, 23 June 2019 (UTC)