HELP! - simple question!

On Fri, 22 Apr 2005 16:15:47 +0000 (UTC), (Brian Tung)
wrote:

*Without* a telescope? That means not even Shoemaker-Levy 9 is in
play, so you're probably limited to supernovae in our galaxy. So,
Kepler's in 1604, Tycho's in 1572, another one in Cassiopeia in 1181,
the Crab in 1054, Lupus in 1006, and two more reported by the Chinese
in 393 and 183, in Scorpius and Centaurus, respectively.

Not to mention an additional supernova every few centuries going back
many thousands of years, until the observers might reasonably no longer
be considered "human". None of these are precisely dated, of course,
although I'm sure that estimates can be made in some cases where we can
observe planetary nebulas.

All of this depends on whether a supernova actually constitutes a
"death" in the sense the OP had in mind. I prefer to think of them as
transforming events. Certainly, the progenitor star continues its
existence, albeit in a quite different form.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Chris L Peterson wrote:
Not to mention an additional supernova every few centuries going back
many thousands of years, until the observers might reasonably no longer
be considered "human". None of these are precisely dated, of course,
although I'm sure that estimates can be made in some cases where we can
observe planetary nebulas.

Sure. There's the Gum Nebula, for one. That must have been some
supernova!

All of this depends on whether a supernova actually constitutes a
"death" in the sense the OP had in mind. I prefer to think of them as
transforming events. Certainly, the progenitor star continues its
existence, albeit in a quite different form.

I think it can certainly be said that Type Ia supernovae are death
events. And if a star is considered to be a fusor, then the other
supernovae are also death events.

Death, after all, is not end of existence. I too will exist after I
die (unless I'm atomized). I just won't be alive.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

On Fri, 22 Apr 2005 18:44:10 +0000 (UTC), (Brian Tung)
wrote:

Death, after all, is not end of existence. I too will exist after I
die (unless I'm atomized). I just won't be alive.

Well, yes, but then a star was never alive in the first place, so this
does very much depend on how "death" is used. Even in the case of a type
1a supernova, you are left with an active object in the same location as
the original pair of objects, and containing lots of the original
material. Death? I don't know. Anyway, it really just word games we are
playing here.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Chris L Peterson wrote:
Well, yes, but then a star was never alive in the first place, so this
does very much depend on how "death" is used. Even in the case of a type
1a supernova, you are left with an active object in the same location as
the original pair of objects, and containing lots of the original
material. Death? I don't know. Anyway, it really just word games we are
playing here.

A star is commonly considered to be a fusor, isn't it? After the
supernova, it ceases to be a fusor. As a star, it dies. It's just
a lump of warm whatever after that, slowly cooling--just like a dead
human being.

I thought a Type Ia supernova commonly resulted in the complete
detonation of the progenitor star--I thought it was the Type II
supernovae that leaves a black hole, or neutron star, or whatever.
The Type Ia's partner might leave around some stuff, but I wouldn't
consider that to be part of the original star.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

On Fri, 22 Apr 2005 21:24:14 +0000 (UTC), (Brian Tung)
wrote:

A star is commonly considered to be a fusor, isn't it? After the
supernova, it ceases to be a fusor. As a star, it dies. It's just
a lump of warm whatever after that, slowly cooling--just like a dead
human being.

Not an unreasonable definition of stellar death.

I thought a Type Ia supernova commonly resulted in the complete
detonation of the progenitor star--I thought it was the Type II
supernovae that leaves a black hole, or neutron star, or whatever.
The Type Ia's partner might leave around some stuff, but I wouldn't
consider that to be part of the original star.

I thought all supernovas leave one or two compact objects behind, but a
little research seems to suggest that type Ia events probably result in
the complete dispersal of the progenitor neutron star. I guess that
qualifies as "death" just about any way you look at it!

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

- he's thinking and looking things up - !
- next round pending -
- Tung the Robot -



Chris L Peterson wrote:

On Fri, 22 Apr 2005 21:24:14 +0000 (UTC), (Brian Tung)
wrote:

A star is commonly considered to be a fusor, isn't it? After the
supernova, it ceases to be a fusor. As a star, it dies. It's just
a lump of warm whatever after that, slowly cooling--just like a dead
human being.

Not an unreasonable definition of stellar death.

I thought a Type Ia supernova commonly resulted in the complete
detonation of the progenitor star--I thought it was the Type II
supernovae that leaves a black hole, or neutron star, or whatever.
The Type Ia's partner might leave around some stuff, but I wouldn't
consider that to be part of the original star.

I thought all supernovas leave one or two compact objects behind, but a
little research seems to suggest that type Ia events probably result in
the complete dispersal of the progenitor neutron star. I guess that
qualifies as "death" just about any way you look at it!

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com