Talk:Supernova

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)

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)

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)

Arianewiki1,

First of all, I am not the originator of the word "nitrogen" that was, once, mentioned in the article. My first edit on the Supernova article was on June 16, 2019: [29], when I added a label to a citation for the mention of "nitrogen" -- the mention of "nitrogen" was already there and, in fact, had been there for a least a year before I came along, see, for example, this version of the article [30] (you can do a word search for "nitrogen"). I hope it is now clear that I didn't do any "original research" as you have suggested so many times.

Second, your concern with whether or not the Johnson source says "about nitrogen" appears to be a misinterpretation of a summary I provided for this edit: [31], where I added the word "about" to the article in front of the word "nitrogen". I was not giving, as you suggest, a "quote from Johnson" -- I've never said "quote from Johnson". My edit summary was simply a summary of what I wrote. The Johnson source shows (her Figure 1) that supernova contribute a smaller proportion of elements lighter than nitrogen, so I thought it worthwhile to qualify the sentence in the article with the word "about". I hope that clarifies things.

Third, I apologise for referring to a sentence as "Arianewiki1's sentence". You had restored a sentence to the Supernova article with this edit [32]. Unfortunately, you did not provide any summary with your edit, so I simply assumed you supported inclusion of this sentence in the article. You might ask yourself whether or not any of this rises to the level of the harassment you've piled onto my talk page: [33].

I don't imagine my responding to your points is going to help this situation. Still, I know I needed to give it a try. Attic Salt (talk) 13:01, 23 June 2019 (UTC)

Simply isn't true. You added this in these five edits here[34] and added a cite that does not say what is have claimed.

As for apologies, upon this edit[35] and saying: "Oh, I see, this is a revert.". Well you should have fully redacted the incorrect text, then do the right thing and openly admit the mistake. (You were asked to do so multiple times, but ignored the request. It is the definition of 'bad faith'. Any reason? I believe you left it there to make me look like a disruptive editor (yet again), 'mudding the waters' to hide away the 'gaming'. In this example, all this could have been avoided by just asking me for a reason for the revert. Instead you saw an opportunity.

Perhaps, you again better take my advice and leave my edits alone. Sure. Fix minor errors, but don't change context. Also stop revert everything on one minor trivial point. e,g. This reverted edit here[36] and all made within a minute of time. (There is not excuse for this kind of editing behaviour, and it validates my complaints. Yet you dismissively say: "I honestly don't see why this is controversial."? How should I feel then?)

The rest written above is dodging the fact sanction gaming, and you were caught out doing it. Again you are responsible for your edits, and you persisted defending a POV by reverts and doing further WP:OR to justify that position - even after being told why it was wrong. This is against policy.

You still repeatably keep wrongly saying and defending: "The Johnson source shows (her Figure 1) that supernova contribute a smaller proportion of elements lighter than nitrogen." It is not true because the source not say this, It is your own opinion made by you looking at some graphic figure, making it original research. That is against policy.

As for: "I don't imagine my responding to your points is going to help this situation." Please. Go right ahead. (In the latest ANI, we're all ears.) Arianewiki1 (talk) 04:52, 24 June 2019 (UTC)

Extended-confirmed-protected edit request

There has been many problems or various problems with recent edits, especially ambiguous reverts. I have recently made a new version, that meets discussions on the talkpage, but this needs better evaluation regarding further changes. It might not be perfect, but it would solve the potential of edit warring or multiple reverts. This article has been mostly stable for sometime, and as a Good article ultimately needs protection. Arianewiki1 (talk) 07:32, 23 June 2019 (UTC)

 Not done: According to the page's protection level you should be able to edit the page yourself. If you seem to be unable to, please reopen the request with further details. — JJMC89 (T·C) 07:50, 23 June 2019 (UTC)

If you want to change page protection levels, see WP:RFPP. Do note however that neither ECP nor semi protection are generally applied preemptively for ordinary articles, even good or featured articles. (TFA is sort of an exception.) Note that neither ECP or semiprotection would have much effect on edit warring or multiple reverts here. Since 13 June, there was a single IP edit quickly reverted [37]. Otherwise every single editor involved is extended confirmed. Hopefully there is no confusion over the difference between ECP and a 1RR page restriction. Full protection may be used when there is ongoing edit warring involving extended confirmed editors but the alternative is to just block those edit warring so the best solution if you're involved is to stop edit warring. BTW this article is technically still WP:Featured article as it has not been demoted. Nil Einne (talk) 03:03, 24 June 2019 (UTC)

Initial Paragraph Issues Further Explained

The Introduction to this 'featured article' is a base summary, and summaries what SNe are in the least amount of words. It is perhaps imperfect, but it has been stable for sometime and is a reasonable compromise. (Considering the long history of this page, the first paragraph has always been modified, and needs unnecessary changes to avoid more problems. e.g. As this restored edit here[38] explained under this section.)

The true cause of supernovae is obviously complex, which is technically just the rare appearance of a type of 'new' bright star. It also is defined as having several processes in a series of events that occurs prior to seeing this 'new' star. e.g. Collapse of core, bounce, then the outburst of the expanding shockwave the quickly brightens then fades over time. (Further explained in 4th paragraph.) It is not just an 'explosion'. (The word 'final' explains the end of the process.)

Also, whilst a type of supernova (Type I) is caused by a heavy white dwarf, the text before this describes "...that occurs during the last stages of the life of a massive star..." The point is that the progenitor of the white dwarf was once a massive star (c. 6 to 8 solar masses), so that this sentence is not contradictory in the broader sense. Saying 'white dwarf' here is clearly unnecessary, and is again further explained in the 4th paragraph. This isn't an arbitrary selection of words and it changes the context.

Much time has been spent by several editors formulating this paragraph and IMO there needs to be a better or fuller explanation for any further modifications.

Further changes should be again discussed on this talkpage if gaining a newer consensus were is required. Arianewiki1 (talk) 01:39, 28 June 2019 (UTC)

Lithopsian in this series of edits has made reasonable changes here[39]. However, this change[40] I think is important to fix because as it usefully removes any difficult complications in having to explain the scenarios between the types of supernova, yet still explain differentiation between kilonovae or novae. e.g. Novae too are caused by white dwarfs.

Attic Salt modifications here[41] has changed the context, as previously discussed. Saying "Unexplained (no edit summary) removal of “white dwarf”, from lede but which is discussed in body of this article.)" Yet this has been discussed previously on this article's talkpage as stated, and is also already further expanded in the Introduction (lede) within the 4th paragraph.

Attic Salt is yet again reminded that edit summaries are not a requirement to edit, and using revert edits (rv) is no justification to revert. It is against policy. Repeatably doing this is now violating rehash and wikihounding, all seemingly done just to cause distress to another editor in the hope of 'nailing them' on some esoteric point. They are also openly reminded of the WP:BRD policy, especially if there is consensus in the community against some specific change you'd like to make. Please break away from this unpleasant repeated cycle of pointy (Do not disrupt Wikipedia to illustrate a point) behaviour. Arianewiki1 (talk) 03:02, 28 June 2019 (UTC)

Oh. Good. God. You are seriously defending this broken-ass edit to the lede of a FA, with its faulty capitalization and punctuation and (due to the lack of an edit summary) complete lack of context that might have otherwise helped another editor figure out what the hell you were trying to do? Of course it was reverted. Cleaning up your messes is not harassment, and your repeated false accusations of such are grounds for a block or ban. You don't own your own edits, much less this page, so you should have no reason to expect that anyone, ever, is going to give a second's thought to your requests for others to not modify your work.

It doesn't appear there is a stable version despite Arianewiki1's self-reference above. I am fine with removing "white dwarf" per this section; "whose dramatic and catastrophic destruction" is terrible writing (a star is not a "who" and the adjectives are hopelessly repetitive); "final" is a useless word; "from sight" is imprecise; and I prefer Arianewiki1's phrasing of "over several weeks or months". So how about [42]? VQuakr (talk) 05:07, 28 June 2019 (UTC)

No. I'm not god. Yet what is truly terrible is your ranting response above. Little of it makes sense, and clearly has some retributive motive of some personal vendetta because of some ridiculous stance you have over edit summaries. Your problem. Yet by complaining of "...complete lack of context that might have otherwise helped another editor figure out what the hell you were trying to do?" means what exactly? I write a few lengthy edit summaries, add this thread to explain why (including its history), and the context is explained and previously discussed several times throughout this talkpage, with a similar version has survived since December 2015. It was gained via consensus, and has been logically explained (Read some of the previous discussions, please.) Yet this is not good enough for you?

• It is 'dramatic' on astronomical timescales.
• It is 'catastrophic' because it destroys the star, but may or may not leave a remnant.
• 'Final' is not useless, because nova can repeat brightening while supernova can do this only once.

Me saying "It is perhaps imperfect, but it has been stable for sometime and is a reasonable compromise." or "Further changes should be again discussed on this talkpage if gaining a newer consensus is required." can hardly be construed as OWN at all.

Making false accusations but then make new false accusations yourself is plainly hypocrisy. Arianewiki1 (talk) 08:37, 28 June 2019 (UTC)

Sure, "you again better take my advice and leave my edits alone" is totally not an ownership red flag. You are not addressing the issue. I am not concerned with the accuracy of each individual word, I am concerned with the quality of the English language sentence you end up with when you mash together a bunch of imprecise and redundant adjectives. Does anyone else think "whose dramatic and catastrophic destruction" is appropriate text for the lede of a science article? VQuakr (talk) 15:59, 28 June 2019 (UTC)

Nice potshot. The real red flag here is going on the attack without any provocation. As for Attic Salt, are you now his mother or protector? I've asked them to leave me and my edits alone because of persistent and repeated sanction gaming. They keep following me and are plainly targeting my edits when they been asked to stop doing it. That is the bigger problem. It is not about WP:OWN at all, it is because they just cannot back off. They want me to stay away from their talkpage and leave them alone, yet they continue on with these pointy surgical strikes.

Editing also takes some competence. which by the 'white dwarf' addition they clearly don't see the problem in why this is wrong, saying "This really is ridiculous. The article discusses SN from both massive stars and white dwarfs. So, the definining first sentence can't mention one without mentioning the other.".[43]

As for the rest, did you even read the initial text above?

Still the point is:

• How fast do stars convert into supernovae?
• How much of the star remains after it goes supernova?

None of that is mentioned in the 1st paragraph. Is it important to say or not? That is why consensus needs to be gained, and not carte blanche rv because you disagree or think something is awkward. Considering the original disputed version survived four years in a featured article makes your assertion fairly inept.

Even more confusing you've said "... am fine with removing "white dwarf" per this section .", then say "Rmv "white dwarf" per Arianewiki1's comment on talk"[44], but now say to Attic Salt below "Works for me. " So which is it, or are you now just sitting on the fence? (After this rv here[45], I assume then this is OK[46]? Arianewiki1 (talk) 02:18, 29 June 2019 (UTC)

A bit more of the phrase that Arianewiki1 wants: "... whose dramatic and catastrophic destruction is marked by a final titanic explosion". This is overdoing it. We might consider the advice of Mark Twain: "As to the Adjective: when in doubt, strike it out." Attic Salt (talk) 19:05, 28 June 2019 (UTC)

The implication that I "want" this statement is false, as article editing doesn't work this way.

If you can improve it do so, but don't change context nor make statements that are already true into something that is false. e.g. Is the statement "... whose dramatic and catastrophic destruction is marked by a final titanic explosion" or is "during the last stages of the life of a massive star or white dwarf, the destruction of which is marked by a titanic explosion." true or false? Statements need to have a epistemic quality of being "ontologically superior" to opinion or interpretation. Also science topics need to have factual conclusions that are influenced by history and consensus, rather than a strictly systematic methodology.

Here, your view is not the only one, and you need to work towards gaining a new consensus not just imposing it. Ironically paraphrasing Shakespeare: "The fault, is not in our stars, but in ourselves." Arianewiki1 (talk) 02:43, 29 June 2019 (UTC)

Since the article discusses SN from both massive stars and white dwarfs, the defining first sentence can't mention one without mentioning the other, otherwise the reader will be confused. Attic Salt (talk) 13:19, 28 June 2019 (UTC)

Works for me. VQuakr (talk) 15:59, 28 June 2019 (UTC)

Umm… As long as you realise nearly all massive stars go supernovae but few white dwarfs go supernova. The statement stated is actually false and a fallacy, not only leaving the reader not only confused but also deceiving them to believe something that is not true. If you believe your statement above is true, you have not comprehended what causes supernovae in the first place. Instead of arguing, let's now test this premise. Arianewiki1 (talk) 03:07, 29 June 2019 (UTC)

Is it possible to be non-specific? Remove mention of massive stars, white dwarfs, or anything else? The only forms of words I can think of are impossibly wooly such as "... that last stages of life of some stars", but maybe there is something better that would keep the lead simple without being mis-leading. I do share previous concerns about the word "destruction". While collapsing into a black hole could be considered pretty destructive, it might be better to find a word that couldn't be taken by some as meaning that there is nothing left behind (beyond an expanding debris field). Lastly, in the vein of "when in doubt, strike it out.", I'd like the drop the word "transient" in the lead. It reads poorly and the phrase "transient astronomical event" sounds tautological to a layman. Lithopsian (talk) 19:53, 28 June 2019 (UTC)

Lithopsian. I agree with most of the above.. I do have concerns that the remnant of supernovae can also be a neutron star/pulsar , and it is difficult to explain either total destruction against some remaining remnant in just of few words. Arianewiki1 (talk) 00:24, 29 June 2019 (UTC)

Something like: "A supernova is a titanic explosion marking the last stages in the life of a massive star or white dwarf". Attic Salt (talk) 20:03, 28 June 2019 (UTC)

Attic Salt saying "This really is ridiculous. The article discusses SN from both massive stars and white dwarfs. So, the definining first sentence can't mention one without mentioning the other." Yet another series of poor pointy edits for someone seemingly without any concept of necessary context. e.g. Saying: "A supernova is a titanic explosion…" shows why this is a problem with you. It is not just an explosion. Then bizarrely you then do this series of edits on core collapse here[47] but don't comprehend its implications.

As for the white dwarf argument, it already appears in the 4th paragraph in the Introduction. What is really ridiculous is saying 'white dwarf' infers that all white dwarfs go supernovae. So do they? Arianewiki1 (talk) 00:11, 29 June 2019 (UTC)

…I just looked up my computer dictionary, that says; "supernova a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass." Surely, not all explosions are catastrophic? Arianewiki1 (talk) 04:31, 29 June 2019 (UTC)

RfC : Inclusion that White Dwarf Stars Go Supernova

The consensus is for a rewrite of the material.

Cunard (talk) 01:17, 11 August 2019 (UTC)

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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Attic Salt contends that : "A supernova is a transient astronomical event that occurs during the last stages of the life of a massive star or white dwarf, the destruction of which is marked by a titanic explosion."[48] They justify this addition by saying: "Since the article discusses SN from both massive stars and white dwarfs, the defining first sentence can't mention one without mentioning the other, otherwise the reader will be confused."[49] Yet they still think: "No, it doesn’t say “all” white dwarfs, but rather “a” white dwarf."[50]

As white dwarf stars above the limit (called the Chandrasekhar limit) of about 1.4 Solar masses will go supernova, but as given in initial statement (above) plainly infers that ALL white dwarfs go supernova.

There is also a contradiction, in that saying: "...that occurs during the last stages of the life of a massive star or white dwarf…", when a white dwarf is considered as ended its life as a star because it no longer creates energy by fusion while energy by a white dwarf is created by gravitational contraction.

This statement is therefore false and a fallacy.

Knowing that the number of these stars near 1.4 solar masses are rare, with the majority being less than this mass. Also these single white dwarf stars were likely once massive stars. Furthermore, the vast majority of massive stars, do go supernova.

Should "or white dwarf" in this statement be removed to fix this fallacy? 04:07, 29 June 2019 (UTC)

• REMOVE. The statement as it is is plainly not true. The inference here makes the reader think that it applies to all white dwarfs. I.e. The Sun's eventual white dwarf will go supernova. (It won't.) If it is necessary to add this, then it must be better qualified to make the statement true. Due to the complexity of the nature of supernova and also making this statement true, "a massive star" is sufficient good to meet the general definition. Arianewiki1 (talk) 04:26, 29 June 2019 (UTC)
• REWRITE. As noted, the article discusses how a supernova can come from either a massive star and or a white dwarf. The inclusion of "white dwarf" into the first sentence was made by Lithopsian: [51]. I support its inclusion because I think that the defining first sentence can't mention one source of a supernova without mentioning the other, otherwise the reader will be confused. The sentence that concerns Arianewiki1 is written in the singular: "a supernova is" and "a massive star or white dwarf". Nothing in the sentence says that "all" white dwarfs result in supernovae. But the sentence certinaly needs work. I have suggested [52] that the sentence might be written as: "A supernova is a titanic explosion marking the last stages in the life of a massive star or white dwarf", but we hardly had time to discuss this or other alternatives before this call for an RFC was made. And, yes, I'm open to discussing alternatives. And here are two alternatives, one of which might make Arianewiki1 happy: "A supernova is a titanic explosion of a massive star or white dwarf." or, less specifically, "A supernova is a titanic explosion of a star." And I'm not intending this last alternative to mean that "all" stars explode! Attic Salt (talk) 12:28, 29 June 2019 (UTC)
• The opening statement of this RfC is neither neutral nor brief. Also, by jumping straight in with the name Attic Salt, it's tantamount to WP:RFC#About the conduct of another user. --Redrose64 🌹 (talk) 15:03, 29 June 2019 (UTC)
• Trout for Arianewiki1 for not paying attention to WP:RFCBRIEF. (On a side note, I don't think mentioning another user's position goes against the section about using RfCs for behavioral problems, since there's no behavior mentioned, but it definitely contributes to the lack of neutrality in the statement). I'd suggest you delete the RfC tag and try again. –Deacon Vorbis (carbon • videos) 16:14, 29 June 2019 (UTC)
• Please, no “binary system” stuff in the first phrase of the article. Aside of being an inappropriately placed boring specification, it doesn’t cover all scenarios possible with white dwarfs. A dwarf may be impacted by an unbound small star (in a dense cluster – why not), or two unbound dwarfs may collide by chance (less probable, but still possible), or a white dwarf may be ignited by impact of some object too small to qualify the system as binary, such as a Jupiter-mass planet. Incnis Mrsi (talk) 16:29, 29 June 2019 (UTC)
• REWRITE. I think the lead section needs a pretty major overhaul and rewrite for a variety of reasons. On this particular point, I do think that it is important to make it clear in the lead section that there are two general classes of supernovae: core-collapse events whose progenitors are massive stars, and explosions of white dwarfs in binary systems. These points do not necessarily need to be in the first paragraph, but they should be in the lead section. It is important to include both classes of supernovae for a few reasons: (a) astronomers usually use the term "massive stars" to mean stars massive enough to undergo core collapse (see Stellar evolution), which is a different category from white dwarf progenitors, (b) white dwarfs are not "massive stars", (c) the progenitors of Type Ia supernovae aren't required to be "heavy" white dwarfs either, there are double-degenerate pathways where two white dwarfs in a binary can collide and trigger a SN Ia even if those white dwarfs are of typical/average mass before colliding. So it's not really necessary or generally correct to say in the lead that SN Ia come from "heavy" white dwarfs, although some of them do. One possible solution to all of this would be for the first paragraph to give a broader general definition that a supernova is a powerful and luminous stellar explosion, which generally brightens rapidly and then fades over weeks or months, and that at peak brightness the optical luminosity of a supernova can be comparable to that of an entire galaxy of stars. To explain the nomenclature, explain the difference between supernovae and novae in that supernovae are far more powerful events, and that a nova is an explosion of a small amount of material on the surface of a white dwarf star while a supernova is an explosion of a star itself. (The current lead section partly does this but doesn't explain that a nova is merely an explosion of material on the surface of a star while a supernova is what happens when a star itself explodes.) Then, in a later paragraph in the lead, the different categories and progenitors of different types of supernovae can be explained briefly. In other words: my proposed solution is to remove from the first paragraph any discussion of what _kinds_ of stars explode: define a supernova as what happens when a star explodes, and then describe the progenitor and explosion types a bit farther down in the lead section where there's a bit more room to explain these points without trying to fit everything into a single all-encompassing sentence about what kinds of stars explode. For the most part, this information is already there in the lead, but the text could be clarified and sharpened up a bit. (Maybe moving the paragraph about Milky Way supernovae to the bottom of the lead section would help to make the paragraph on progenitor types more prominent.) I would also suggest removing any references to stellar "life" from the lead: in my view this kind of anthropomorphising can cause confusion, even though astronomers do use this terminology loosely. For massive stars we can correctly say that core collapse occurs at the end of the star's evolution. For white dwarf explosions, it's probably best to avoid the "life" analogy altogether, to avoid confusion. Aldebarium (talk) 17:35, 29 June 2019 (UTC)

I've tried to follow up on this idea, following on from another edit. I made the first sentence much simpler, basically "its a big bright bang". Then the rest of the first paragraph tries to cover the various possibilities. It may not be perfect yet, but I think the structure will let us be clear and complete without trying to cram a confusing mass of information in before we've even told the reader what a supernova is. Lithopsian (talk) 14:21, 30 June 2019 (UTC)

• REWRITE. In line with the other rewrite votes so far. In any case the text as it is presented here cannot stand. JonRichfield (talk) 04:55, 30 June 2019 (UTC)
• Trim: Compare to the lead that was used for the FA promotion here, it has migrated quite a bit. Entropy happens, I suppose. I don't believe it now satisfies MOS:LEADLENGTH, so it needs to be trimmed down. Praemonitus (talk) 14:56, 12 July 2019 (UTC)

Chop away! I'm not sure the lead is too long for a very detailed and complex article, though. I've looked at the lead to see what I might want to drop, and it isn't much, but then I've been too close to the article for a while and fresh eyes would help. Lithopsian (talk) 15:03, 12 July 2019 (UTC)

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The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Silicon Burning

How would silicon burning occur to produce ⁵⁶Ni in Type Ia supernovae, if silicon burning occurs at a minimum of 8-11 solar masses, but white dwarfs reach critical mass at 1.4 solar masses? It's said in the second paragraph of the energy output section.

Strombolian (talk) 03:02, 19 September 2019 (UTC)

Where does it say silicon burning can only occur for a minimum 8-11 M_☉ star? And more importantly, where does it say it can only occur in a supernova from an 8-11 M_☉ star? A very high proportion of the initial mass of the white dwarf (probably carbon and oxygen plus a few bits and pieces, possible neon, magnesium, a little accreted hydrogen) fuses all the way to "iron" (technically nickel which then decays radioactively), with the last stage being silicon burning. There really isn't any other significant way to reach the iron peak elements. Plus the references say so. Lithopsian (talk) 13:18, 19 September 2019 (UTC)

Please fix number of visible supernova

Hi,

I added a citation needed on this page for the number of supernova observed in the Milky Way. The first citation needed is when it says only 3 supernova have been visible over the last thousand years. On other wiki pages like 'History of supernova observation' it mentions the following supernova have been observed, SN 1006, SN 1054, SN 1181, SN 1572 and SN 1604 which is 4 or 5 (depending on how strictly you want to adhere to thousand years).

The other citation needed is under the observation history where it says "Before the development of the telescope, only five supernovae were recorded." Again, from other sources there are certainly more than five recorded supernova as you have the five stated above along with SN 393 and SN 185 for at total of at least seven.

Can we get an expert to fix this issue and let us know how many visible supernova have been observed in the Milky Way? — Preceding unsigned comment added by 2001:569:77fd:400:1c39:1993:290a:6e4b (talk • contribs) 03:05, 22 December 2019 (UTC)

Removed. DrKay (talk) 17:08, 24 December 2019 (UTC)

Effect of rotation eg on core-collapse or GRB

Can we say anything on how the rotation rate of the progenitor might affect core-collapse supernovae, eg. might it affect the strength or beam open angle of a GRB ? - Rod57 (talk)

Do you have any WP:RS pertaining to that information? if you post it , an editor might look further into it.MaximusEditor (talk) 01:35, 28 January 2021 (UTC)

Pick a spelling

The article contains a mix of British and American spelling-isms. The general rule is to pick one and stick to it, going with the predominant spelling style unless there are compelling reasons otherwise. What do people think is the predominant style at the moment? Lithopsian (talk) 19:38, 2 September 2020 (UTC)

I say this as an American - I strongly believe the entirety of Wikipedia should be converted to "British" spelling (which is a bit of a misnomer; the same spelling is used in Australia, New Zealand, Canada, and the rest of both the English-speaking world and most of the rest of the world when writing in English.) The majority of the world's English speakers spell it "colour" and "realise". (While on the topic, I'd also like to see Imperial measurements expunged from science-based articles!)

However, if the general rule is to pick one and stick with it, I'd go with whichever spelling convention is currently in the majority of the article. Khardankov (talk) 13:58, 27 November 2020 (UTC)

Standardized (sic) in British spelling and tagged. Might be more to fix. 2A02:C7F:7428:D200:D41E:8807:3458:2B32 (talk) 13:58, 28 November 2020 (UTC)

Old galaxies

Under "Current Models", it is mentioned that "older, more distant" galaxies have lower metallicity. I find this use of "older" confusing. Surely, it is younger galaxies that have low metallicity, and distant galaxies are young galaxies as we see them now? Sure, distant galaxies will be old by the time we see them, if they're even still around, but that's not relevant to the context, right? Acquirium (talk) 18:36, 21 October 2020 (UTC)

Request

Please create an edit notice for the article, placing in it the template {{British English|form=editnotice}} Thank you--2A02:C7F:7428:D200:D41E:8807:3458:2B32 (talk) 14:06, 28 November 2020 (UTC)

 Done Ruslik_Zero 14:20, 28 November 2020 (UTC)

WP:URFA/2020

There is very significant uncited text in this article. If this is not addressed, a featured article review may be needed. Hog Farm _Talk 17:48, 22 February 2021 (UTC)

Electron-capture supernovae 2018zd

We have a type III supernova now. I think we should separate Type III into it's own section and cover 2018zd. paper, Anton Petrov youtube video Daniel Santos (talk) 17:16, 9 July 2021 (UTC)

Stellar mergers

As reported below, another cause seems to be merger of a large star and a neutron start or black hole. Is this in the article ? (It's very long, & I haven't time to read every paragraph). <https://www.popsci.com/space/rare-supernova-merger-observed>

<https://www.space.com/new-type-supernova-star-merger>

The Yeti (talk) 16:55, 12 September 2021 (UTC)

Steady State Universe

In a Steady State Universe, stellar explosions must be conserved. The same star explodes over and over again. It somehow quickly gains enough mass to overwhelm the energy-mass equilibrium of the star, meaning the star builds up energy-mass until the star explodes. Equilibrium is thereby regained, the mass ejected from the explosion eventually falls at once back into the star, and the runaway instability repeats itself. I assume that the expansion of mass powers stars not fusion reactions, which are incompatible with Steady State. (This expansion is relatively non generalist).GuildCompounder (talk) 21:07, 1 November 2021 (UTC)

"Radio supernova" listed at Redirects for discussion

A discussion is taking place to address the redirect Radio supernova. The discussion will occur at Wikipedia:Redirects for discussion/Log/2021 November 12#Radio supernova until a consensus is reached, and readers of this page are welcome to contribute to the discussion. ~~~~
User:1234qwer1234qwer4 (talk) 20:27, 12 November 2021 (UTC)

"Supernova 2" listed at Redirects for discussion

A discussion is taking place to address the redirect Supernova 2. The discussion will occur at Wikipedia:Redirects for discussion/Log/2021 November 12#Supernova 2 until a consensus is reached, and readers of this page are welcome to contribute to the discussion. ~~~~
User:1234qwer1234qwer4 (talk) 20:33, 12 November 2021 (UTC)