What is the temperature of a supernova?

[Loren Pechtel]

This came up on another board. Google is letting me down horribly on this, though--I'm getting three wildly different answers.

[Demosthenes]

There are two types of supernovas. One resulting from the collapse of a massive star(type 2) and a runaway explosion occuring when massive amounts of material has been deposited on a white dwarf in a binary system(type 1)

Futher, there are also several subcategories. But I'm assuming you're referring to type 2 supernova. So far all of my searches in various astronmy resources have turned up values roughly clustering around 100 million degrees Kelvin. I'd imagine that it depends a lot on the exact mass of the star. But 100 million degrees seems a reasonable layman's answer.

[Darth Dane]

I'd say hot! ;)

[Loren Pechtel]

There are two types of supernovas. One resulting from the collapse of a massive star(type 2) and a runaway explosion occuring when massive amounts of material has been deposited on a white dwarf in a binary system(type 1)

Futher, there are also several subcategories. But I'm assuming you're referring to type 2 supernova. So far all of my searches in various astronmy resources have turned up values roughly clustering around 100 million degrees Kelvin. I'd imagine that it depends a lot on the exact mass of the star. But 100 million degrees seems a reasonable layman's answer.

100 million K is way too low. The numbers I was finding are 1B K, 10B F, 100B unspecified.

[Semblance]

My "Astrophysics I" textbook, written by Richard Bowers and Terry Deeming mention several temperatures, 10^9K and 10^11K. That's the core temperature. The photosphere (the surface) is much cooler, on the order of 10,000K.

[Demosthenes]

I went back to my search engines and realized that I had mistook the 100 million K temperature which occurs when a star start to fusion helium. Here are two webpages that have temperatures for the range of fusions that occurs as a star progresses to a supernova. So far the temp number for a supernova is over 600 million K.

Evolution of stars (http://www.milky-way.com/gb/sevol.htm)

Stellar Evolution (http://www.pd.astro.it/hosted/MOSTRA/E-MOSTRA/NEW/A3003EVO.HTM)

[quartodeciman]

It is interesting that most stars seem to live the earliest and main part of their lives in relative quiet and bliss (Hydrogen core burning phase). They start to get dramatic and wild late in life (Hydrogen core replaced with synthesized atoms), first going toward red giant and supergiant phases, swinging between high and low surface temperatures, and possibly dramatic climaxes. Flame out! The most important determinant seems to be the total mass of the original condensed protostar. This, plus any mass accreted during the post-formation lifetime of the star seems to tell the whole story. Rotation of the protostar, which affects mixing of constituent types of atoms has some effect in the star's life story. Actual mixture of original elements is less important, as long as Hydrogen dominates. Low mass stars basically wimp out as brown or white dwarfs and have very long middle age of stability; high mass stars end up needing to blast off most of their mass late in life after a comparatively short period of stability.

[Jesse]

How about the temperature at the center of a supernova large enough to form a black hole? Would the temperature ever approach the Planck temperature (http://www.planck.com/plancktemperature.htm), around 10^32 K? If not, are there any circumstances in which this temperature could be approached other than the big bang?

edit: thinking about this some more, I'd guess this temperature would probably only be approached inside the event horizon, when the matter forming the black hole becomes compressed enough that quantum gravity takes over, maybe when it has a density of one planck mass per planck volume...

[Dark Jedi]

Here is the rub:

Which supernova? Specifically?

The question is somewhat flawed in that it is overly general.

Example: How hot is fire?
Which fire? What fuel, in what quantity and mixture?

Which star? At what density? How far along was the nuclear reaction when it went supernova? What percentage of fusionable material was consumed by the expansion?

Best you can hope for is a theoretical range. I would hypothesize it was between 0 degrees K and Planck.... your research may narrow that down :D