Talk:Hypernova

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[edit] NOTE

this article doesn't explain that initially it was believe that gamma ray burst "hypernova" were believed to be a spherical ejection of matter. It was a great mystery, how could a star release so much energy in all directions. It was only later when they realised that the burst was confined to a polar burst that the numbers started to add up. This isn't mention in this article, and was a critical moment the development of an understanding of the universe. I'm not the best writer, so I shall let one of you guys add the info. —Preceding unsigned comment added by 84.9.41.15 (talk) 13:00, 7 June 2008 (UTC)


[edit] Merge or split first and discuss later

Since no action's occured regarding split I've removed the notice from the article and consolidated all prior discusssions within this section. – Conrad T. Pino (talk) 05:05, 2 February 2008 (UTC)

[edit] Collapsar page

All right, if there are no comments on my previous post, then I will go ahead and create a collapsar page and only once that is done, remove the collapsar stuff on the hypernova page here.

Hypercott 18:04, 26 October 2007 (UTC)

[edit] Proposal: Split up Hypernova and Collapsar

The term collapsar should be described independently from hypernova. I would like to take part of the collapsar discussion and move it onto a separate Collapsar page. At the same time, I volunteer to fix the science issues of this article... (I am a supernova/GRB theorists and feel capable of doing it)

Comments? Hypercott 20:20, 23 October 2007 (UTC)

The terms should definitely be split. Orcoteuthis (talk) 20:32, 9 January 2008 (UTC)

[edit] Proposed merge of collapsar and hypernova

These articles were tagged for merging by User:Cwolfsheep. Discussion to determine consensus opinion about the merge (if consensus exists) goes here. --Christopher Thomas 06:43, 6 July 2006 (UTC)

  • Do not support merging of collapsar with hypernova. A collapsar is a specific physical model for the central engine of long duration gamma-ray bursts. Hypernova, means different things to different astrophysicists including pair-instability supernovae of very massive metal-poor stars. Hypernova is also used to describe any stellar explosion thought to be more energetic than canonical supernovae. It is true that collapsar was used as a generic term for black holes a long time ago, but it is now commonly understand in the astrophysics community to be a model for long GRBs involving the rapid accretion of gas into a newly-formed spinning black hole formed during core collapse of a rapidly rotating Wolf_Rayet star. —The preceding unsigned comment was added by Black hole (talk • contribs) on 18 July 2006.
  • Oppose per Black hole. 132.205.44.134 02:28, 25 July 2006 (UTC)
  • Oppose because neither of the definitions have reached stability of usage even in the professional community. Hypernova was used in the late 90's to refer to the putative 10<sup53 erg explosions required to power unbeamed gamma-ray bursts. Now that it is widely agreed that they are heavily beamed, the term is being used for SNe only slightly more energetic than average. Collapsar is undergoing similar evolution -- it currently seems to be applied to GRB progenitors, but who knows if that is where the term will settle. Mordecai-Mark Mac Low 15:11, 25 July 2006 (UTC)
  • Oppose a full merge per reasoning above, as e.g. user Black hole. However, the paragraph about the collapsar model (currently the third paragraph) should maybe be lifted out from here and merged, as it's specifically talking only about the collapsar theory, and that would then more properly be covered in its own article. -- Northgrove 23:19, 5 August 2006 (UTC)

[edit] Hypernova spelling

"Hypernova (pl. hypernovae)" The term nova is the plural of the latin term novum and is in its current singular meaning in no way latin. Why then not novas?--80.146.2.242 22:53, 28 August 2007 (UTC)

Nova is here not the neuter plural but the feminine singular - it's originally short for stella nova "new star" - and novae is very much the correct Latin plural. In fact, hypernova, pl hypernovae would be a good neo-Latin word. Orcoteuthis (talk) 20:24, 9 January 2008 (UTC)

[edit] Removed section

I removed a section that was uncited and directly contradicted cited parts of the gamma ray bursts page. Plus I'm pretty sure what was written is just untrue.67.82.47.139 23:25, 9 January 2007 (UTC)

[edit] Rate of occurrence

Regarding: "It is estimated that a hypernova occurs every 200 million years. That would mean the Earth is past due by 250 million years."

Does this imply (incorrectly) that hypernovae are fairly regular events? The probability of a hypernova occurring today is no more or no less than it was 200 million years ago. Yet someone reading this sentence could be mislead by the Gambler's_fallacy into assuming that a hypernova was imminent.

My guess is that a hypernova occurs more often in the galaxy than only once in every 200 million years, since the galaxy contains trillions of stars.
I think the the statement in the article relates only to the Milky Way, or even only the solar system.
So a hypernova has not occured in this region for about 250 million years. Patrick1982 08:34, 27 July 2005 (UTC)
Your point stands, but the Milky Way Galaxy "only" contains about 100 to 400 billion stars. Billbrock 04:04, 15 October 2005 (UTC) edited Billbrock 07:03, 23 October 2005 (UTC)

I removed the offending sentence. I felt it was very misleading. (Dean P Foster)

Some web pages have suggested Eta Carinae as a candidate in our galaxy to turn into a hypernova within the next million years.

And web pages, naturally, are the ultimate source of information on astrophysics. -- CYD

I removed the web pages linked to that provided the debated information. If the text there is considered too misleading to be included in the wikipedia, it's hardly a good source. Suspecting that the "some web pages" part in the "OMG ETA CARINAE IS GOING TO KILL US ALL" line refers to the very same page, I removed that sentence as well. Enough is mentioned about this star in the end of the article I think, without the doomsday prophecies. -- Robert

[edit] Safe for Foreseeable Future

The following still makes me uncomfortable.

If hypernovae only occur in massive stellar objects at least 40 times the mass of our sun, then the Earth is safe from such an event for the foreseeable future. The closest hypernova candidate, Eta Carinae, is currently over 7,500 light years away.

Perhaps there are sensors faster than light that I know not of, but I would guess that all we know is that 7,500 years ago the star was 7,500 light years away. Currently it may be a black hole and a bunch of gamma rays. If it went hypernova 7480 years ago, then I don't think we'd know it yet, but it could affect us in the foreseeable future. Am I missing something? (Of course it could just as easily be hundreds of millions of years from any such fate.) Dpv 00:27, 16 May 2006 (UTC)

Yes, you're missing something: the energy will spread out as r-2, so the danger drops as the square of the distance. 7500 light years is a substantial distance, even for a GRB. Mordecai-Mark Mac Low 19:36, 28 May 2006 (UTC)

You are also forgetting that stars move in the galaxy, so we could end up right next to a potential supernova! —Preceding unsigned comment added by 80.235.132.32 (talk) 09:37, 31 January 2008 (UTC)

Yes, but remember that if we get that close to a star, there will be adverse effects before that happens due to the gravitational pull and the heat from that star. Viet|Pham (talk) 01:38, 17 May 2008 (UTC)

[edit] Removal of extinction section

I've removed the following content entirely, as it is already included in the article on gamma ray bursts, which is a more appropriate location.

Hypothetical scenarios involving Earth
It has been theorized that the energy released by a hypernova relatively nearby might be capable of causing mass extinctions on Earth. Scientists at NASA and the University of Kansas in 2005 released a study suggesting that a mass extinction on Earth 450 million years ago, known as the Ordovician extinction, could have been triggered by a gamma-ray burst. Hitting the Earth for only ten seconds, a gamma ray outburst caused by a hypernova could deplete up to half of the atmosphere's protective ozone layer. With the ozone layer damaged, ultraviolet radiation from the Sun could kill much of the life on land and near the surface of oceans and lakes, and disrupt Earth's ecology.
If hypernovae only occur in massive stellar objects at least 40 times the mass of our sun, then the Earth is safe from such an event for the foreseeable future. The closest hypernova candidate, Eta Carinae, is currently over 7,500 light years away.

Mordecai-Mark Mac Low 17:03, 29 May 2006 (UTC)

[edit] Coinage

The book "Death by Black Hole" by Neil DeGrasse Tyson, states that the coinage of the term "Hypernova" belongs to the Princeton astrophysicist, Bohdan Paczynski (p.280), yet this article states otherwise; should it be changed? —Preceding unsigned comment added by 68.165.186.66 (talk) 01:12, 27 October 2007 (UTC)