Talk:Supernova

Red supergiant problem

The concept of the red supergiant problem was mentioned very briefly in this article, now slightly less briefly. It now has its own article which I feel is unhelpful out of context and not sufficiently notable in its own right. Hence, redirect it here and expand if necessary. Lithopsian (talk) 13:55, 31 March 2022 (UTC)

Merged. Lithopsian (talk) 12:02, 5 May 2022 (UTC)

The energy balance of supernova type II

A fusion of iron does not release energy, contrary to what is written on Wikipedia. This is a major error. Instead, a fusion of iron demands energy. It is accepted that what happens is not a fusion of iron, but the disintegration of iron to helium and then to hydrogen. However, the disintegration of iron also demands energy. Considering the accepted known processes, there exists a huge energy deficiency. If so, no explosion of type II supernova should occur. However, thousands of supernovae explosions were observed. This is why supernova type II is listed in the list of unsolved problems in physics. Actually, the non-trivial solution to the energy balance of supernova type II is given in the free peer-reviewed paper (2015)

https://doi.org/10.1088/1742-6596/615/1/012012

Netsivi (talk) 07:50, 23 May 2022 (UTC)

Where does Wikipedia say this? Lithopsian (talk) 10:26, 23 May 2022 (UTC)

In “core collapse” section: “The collapse may cause violent expulsion of the outer layers of the star resulting in a supernova, or the release of gravitational potential energy may be insufficient…”, later described in the section: “failed supernova.” Netsivi (talk) 13:16, 23 May 2022 (UTC)

Also "from fusion rendering the star incapable of counteracting its own gravity, usually occurring after the fusion of iron in a star’s core, releasing gravitational potential energy as a supernova."

Netsivi (talk) 13:46, 23 May 2022 (UTC)

I've changed that sentence in the lead, it was overly vague about the collapse mechanism and still managed to imply some things that aren't correct. The rest of it I don't see. The section you mention, and the text you quote, doesn't discuss iron fusion anywhere. If you just want to promote the theory in the paper you mentioned, try editing the article and see what people think. Or just edit the sections you think are a problem anyway, instead of trying to have people guess what it is you really want to say. If you can't edit this article because of protections, then you can do it in your own sandbox. Otherwise this just seems like pin the tail on the donkey. Lithopsian (talk) 13:59, 23 May 2022 (UTC)

Following Lithopsian’s suggestion, the explanation of the energy balance is added to enable responses. Please do. Netsivi (talk) 15:45, 24 May 2022 (UTC)

Well, I guess that counts as a comment! On the positive side, I see what you're trying to get at, but stylistically it wasn't a good edit: the prose style was not encyclopaedic (see WP:MOS and links), it didn't fit into context in the article (too much like an essay parachuted in), and it was too technical and detailed even in a highly detailed article. As a way forward, maybe modify an existing section describing the process (eg. Core collapse - detailed process) to reference the energy balance issues better, then you can add some short descriptions of possible solutions. Overall, I wouldn't have thought the existing sections on models need to be a whole lot longer, the article is already pushing sensible limits on length. Also, think about how to summarise in one sentence or less that can go in the lead. An alternative is to try a whole new article, but that has its own hurdles to overcome; for example, just taking what you wrote and making it a separate article would quite possibly be rejected. A separate article would give more scope for detail, though, but this article as a "parent" would need a short summary section and a link to it. Creating new Wikipedia articles is a whole learning curve in itself. It is often easier to expand existing content, and then WP:SPLIT it into a new article if it gets out of proportion to the rest of the article; more difficult here because this is a featured article (under review) and is closely monitored to maintain its quality. Lithopsian (talk) 21:17, 25 May 2022 (UTC)

Thanks. Supernova is indeed confusing. Imagine a simple experiment:

A scientist drops a simple flexible ball. It bounces back from the floor, hits the ceiling, smashes the ceiling to pieces and takes the pieces with it, and together takes off to the space. The scientist repeats the experiment and obtains the same impossible result thousands of times. Confusing? Of course, but this is what seems that a supernova type II does. Mother Nature knows better.

Is the following clear and appropriate for Wikipedia to describe what really happens in a supernova type II? (Without sentences copied from papers, and following your suggestion, adapted to embed at the end of “Core collapse – detailed process”)

===== The energy balance of supernova type II =====

The explosion of supernova type II is preceded by the implosion of the progenitor star. The processes that cause the implosion are known, but the processes that reverse the implosion to an explosion are not known. Therefore, supernova type II is considered an unsolved problem in astrophysics.

====== Definition of the unsolved problems ======

The source of energy of the explosion is considered unknown.

During the stages of a supernova, the energy changes form from gravitational potential energy to kinetic energy and vice versa, while obeying the laws of physics, namely the conservation of energy and the conservation of the angular momentum.

During an implosion, the gravitational potential energy is gradually transformed into the kinetic energy of fast velocity inward. Near the center of the star, the motion is momentarily stopped, and the layers lack kinetic energy.

The energy is then accumulated as potential energy. At the same time neutrino production and disintegration of iron nuclei to helium alpha particles and to hydrogen protons demand energy that has to be supplied. Immediately the accumulated potential energy is transformed into the kinetic energy of fast velocity outward. As the layers move outward, they gradually lose kinetic energy which is transformed into gravitational energy. When reaching the surface of the star, or earlier, all the kinetic energy is already transformed into gravitational potential energy according to the conservation of energy, and the motion outward should be stalled. Numerical simulations show that no kinetic energy of movement outward is left.

However, thousands of supernova observations exhibit a huge excess of kinetic energy, that ejects the matter outwards with velocities of thousands and tens of thousands of km/sec for thousands of years.

Therefore, the problems that are considered unsolved are:

How is the potential energy accumulated momentarily near the center of the star when the implosion is already stopped, but the motion outward did not yet start?

How the huge necessary excess of energy that later ejects the matter of the star outward in velocities of thousands and tens of thousands km/sec is produced just then while obeying the laws of physics?

====== Solution to the energy balance in supernova type II ======

Two possibilities for momentary energy accumulation near the center of the star were suggested, as well as a different possibility of energy production.

1. The final collapse is fast, about the order of a thousandth of a second. There is no time for the slow process of weak capturing of an electron in the proton so as to be transformed into a neutron (which needs about a quarter of an hour). Instead, each electron populates an orbit in an additional set of orbits, extremely close to the proton. The velocity of the electron in this additional orbit approaches the speed of light, and its fast motion accumulates a lot of energy by the relativistic increase of its mass and energy.

2. Later the gravitational field is over-compressed and constitutes yet another accumulator of energy.

3.

A different process produces kinetic energy by annihilating quarks according to the relativistic equation E=mc². The high pressure compresses the quarks to each other until they interpenetrate, and their spin is quenched. Their kinetic energy of rotation is higher than 99% of their mass multiplied by c². This intrinsic kinetic energy of the self-rotation of the quark is transformed into the excess of kinetic energy that ejects the matter of almost the entire star outside of the star in a supernova explosion with a velocity of thousands or tens of thousands km/sec. Transforming half of a percent of the matter of the star to kinetic energy is sufficient to eject the matter of the entire star at a velocity of thousands or tens of thousands km/sec. Netsivi (talk) 05:51, 26 May 2022 (UTC)

WTF?!? Why are you telling me all this? Are you here to improve Wikipedia or just trying to get something off your chest? Lithopsian (talk) 14:40, 26 May 2022 (UTC)

You advised me. Thanks. I made changes accordingly, and wanted to know whether they are sufficient in your opinion. Or, am I allowed to add them without bothering you. Netsivi (talk) 20:15, 26 May 2022 (UTC)

This time it was removed not because of being confusing, but because "content written in non-encyclopedic style" Netsivi (talk) 19:37, 27 May 2022 (UTC)

So I see! I'm not surprised, though. There seems to be a bit of a disconnect what Wikipedia expects and what you think it needs. That is quite common for new editors. Your writing style seems to be a combination between essay and sales pitch, neither of which is suited to Wikipedia. This can be daunting with your first few hurdles, but most new editors start with something that isn't a featured article and take small bits to start out. There are guides: start at Wikipedia:New contributors' help page.

Perhaps ultimately more important, you seem to have something incredibly pressing to communicate to the world, but it isn't a widely-accepted explanation for how supernovae occur. Wikipedia only conveys consensus opinion on a subject, and possibly a few leading theories for unsolved problems. What you are writing about appears to border on WP:FRINGE: it is formally published, but not widely-cited, and certainly not a consensus theory. IMO, it isn't even in the running, but I may be wrong and I just haven't caught up with this yet.

Lastly, Wikipedia frowns on editors having a close connection to a subject. While it isn't completely banned, it is discouraged because of real or perceived conflicts of interest or an inevitable non-neutral point of view on the subject. In particular, editors should disclose any close connection, but better yet, you shouldn't try to overwhelm articles with your own theories, published or otherwise. Perhaps to start with, you could disclose your own connection and then try to edit the article in simple non-controversial ways. Lithopsian (talk) 20:41, 27 May 2022 (UTC)

References

These supernovae would almost certainly be observable with modern astronomical telescopes ...

This sentence is problematical. It refers to supernovae described in the previous sentence, but the previous sentence makes mention of two sets of supernova, so "these" is ambiguous. It could also seem slightly confusing, since we've had modern astronomical telescopes for at least 30 years and so would have expected to observe these supernovae as described. What the sentence is really saying is that any Milky Way supernova that occurs "now" would be expected to be visible in our modern equipment. I'm struggling to reword it in a way that is unambiguous, perhaps alluding to the unexpected lack of recent detected supernovae, but still succinct enough for the lead. Any ideas? Lithopsian (talk) 21:00, 9 March 2023 (UTC)

I took a stab at revising that paragraph, but I'm certainly not committed to my phrasing. XOR'easter (talk) 14:46, 10 March 2023 (UTC)

Naming convention

The existence of "three-digit designations" needs to be better explained, particularly with SN 2023ixf. Urhixidur (talk) 13:19, 27 December 2023 (UTC)

occurred vs. observed

The following sentence should be edited, "The brightest recorded supernova was SN 1006, which occurred in AD 1006" with the word "occurred" replaced by the word "observed". (This page is protected so I can not edit it myself.) Philip Tymon (talk) 02:30, 6 January 2024 (UTC)

Fixed. Thank you. Praemonitus (talk) 20:28, 16 May 2024 (UTC)

Frequency in the the Milky Way

The article currently says supernovae occur in the Milky Way on average about three times every century. This rather contradicts the statement about Kepler's Supernova in 1604 where four centuries have passed without any new observed supernova in the Milky Way. Any thoughts on how to reconcile this? Brandmeister^talk 12:12, 6 January 2024 (UTC)

If there is enough extinction from interstellar dust, a supernova in the Milky Way can go unobserved with the naked eye. Kepler's supernova was 6 kiloparsecs away, whereas the Milky Way is 27 kiloparsecs across. Praemonitus (talk) 20:26, 16 May 2024 (UTC)

Inaccuracy in diagram of the periodic table under "Source of heavy elements".

In the image, it states that the elements Technetium (Tc) and Promethium (Pm) are only made via human synthesis, and not naturally. However, this is not true, as the forementioned elements occur naturally via radioactive decay, and promethium has even been found in the emission spectrum of a star in the andromeda galaxy (GY Andromedae). I am not sure where to find another image to replace the incorrect one, but if anyone could, it would be helpful to correct the false information. ScienceCider (talk) 14:45, 27 February 2024 (UTC)

@ScienceCider the first step is to find reliable references for the these claims. The current section is referenced as is the image. Johnjbarton (talk) 16:38, 27 February 2024 (UTC)

I believe it has to do with the radioactive half-life of these elements, not in how they are produced. Per this old paper, Technitium can be produced in supernovae. However, most of the isotopes of those elements have half-lives measured in days or years, so you wouldn't see them in the general ISM. See the original paper.

Sivaram, C.; de Sabbata, V.; Yellappa, Y. (1990), "High Energy Gamma Ray and Neutrino Production of Technetium in Supernovae and Red Giants", Proceedings of the 21st International Cosmic Ray Conference, vol. 4 (OG Sessions), p. 472, Bibcode:1990ICRC....4..472S.

Praemonitus (talk) 16:52, 16 May 2024 (UTC)

Reverted addition

The text

• Of the 147135 (extra-galactic) supernovae observed between 2000 and 2023, 21297 have been typed, with 76.5% being Type I.

was added twice and I removed it twice. It is not sourced. It is also not notable unless there is a reference telling us why it would be. Note that Wikipedia links provide context, but are not reliable sources as references. Johnjbarton (talk) 14:57, 1 June 2024 (UTC)

The stats on Wikipedia are properly sourced, the totals mechanically derived from these. I would change "76.5%" to "about three-quarters" to avoid having to keep them in sync. And not notable? Such a basic stat is self-evidently notable. I came to the supernova article looking for the relative proportions of the two types, didn't find it directly mentioned, but found it indirectly mentioned. 115.69.29.10 (talk) 15:26, 1 June 2024 (UTC)

Sorry, but I disagree. The construction of this information by analysis of the literature is a kind of research. Why do you want to add this paragraph? I guess because you believe the observed fraction is significant. But there are many possible causes for 3/4 Type I. The observations could be bias towards Type I for many reasons: Type I are more interesting, are more visible, because some Wikipedia editors picked them to include in a table, and so on. Why aren't the other 120,000 typed? Without a reference to analyze the 3/4 it just not information in the Wikipedia sense.

I think the relative abundance of types of Supernova should be discussed with proper references, not implied looking at a table of randomly selected links on a web page. Johnjbarton (talk) 15:37, 1 June 2024 (UTC)