Yet another oldest Supernova ever

I'm getting a little confused by these announcements. Today they
announced that they have discovered the oldest and farthest supernova
ever, at nearly 11 billion light-years. But just a few weeks back,
didn't they announce the oldest, farthest Gamma-Ray Burst, which would
also be a type of supernova. And the GRB was farther away still, at over
13 billion light-years.

Most Distant Supernovae Found
""The ones that we've detected happened about 11 billion years ago, so
you're getting close already," said lead author Jeff Cooke, an
astronomer at the University of California, Irvine. "
http://news.nationalgeographic.com/n...supernova.html

The previous announcement, about the oldest GRB they found was in this
thread:

sci.astro | Google Groups
http://groups.google.com/group/sci.a...dd3c5a0e5f737d

Yousuf Khan

Sam Wormley wrote:
So did you sort out to your satisfaction the details and differences
between these observations?


No, enlighten me.

Yousuf Khan

On Jul 9, 9:00*pm, Yousuf Khan wrote:
I'm getting a little confused by these announcements. Today they
announced that they have discovered the oldest and farthest supernova
ever, at nearly 11 billion light-years. But just a few weeks back,
didn't they announce the oldest, farthest Gamma-Ray Burst, which would
also be a type of supernova. And the GRB was farther away still, at over
13 billion light-years.

Most Distant Supernovae Found
""The ones that we've detected happened about 11 billion years ago, so
you're getting close already," said lead author Jeff Cooke, an
astronomer at the University of California, Irvine. "http://news.nationalgeographic.com/news/2009/07/090708-most-distant-s...

The previous announcement, about the oldest GRB they found was in this
thread:

sci.astro | Google Groupshttp://groups.google.com/group/sci.astro/tree/browse_frm/thread/3dabd...

* * *Yousuf Khan

It's a bit like religion.

Hardy

Sam Wormley wrote:
Yousuf Khan wrote:
Sam Wormley wrote:
So did you sort out to your satisfaction the details and differences
between these observations?


No, enlighten me.

Yousuf Khan

http://www.skyandtelescope.com/commu.../50249452.html

This is just another article about the same story I previously posted in
this thread. What I was asking about was if people had previously
discovered GRB's at 13 billion light-years already, then why are these
people saying that these supernova at around 11 billion light-years are
the farthest out yet? 13 billion beats 11 billion doesn't it?

Yousuf Khan

Dear Yousuf Khan:

On Jul 9, 9:44*pm, Yousuf Khan wrote:
Sam Wormley wrote:
* So did you sort out to your satisfaction the
details and differences between these
observations?

No, enlighten me.

Not all GRBs are supernovae. More correctly, a supernova has to have
other characteristics, including a certain duration / luminosity
relationship.

David A. Smith

On Jul 10, 3:15*pm, dlzc wrote:
Not all GRBs are supernovae. *More correctly, a supernova has to have
other characteristics, including a certain duration / luminosity
relationship.

I think in this case, they did identify this GRB as a supernova. I
guess the other possibilities for GRBs are Active Galactic Nucleii.
AGN's are usually long-duration, while supernovas are short duration
GRBs.

In article ,
Yousuf Khan writes:
didn't they announce the oldest, farthest Gamma-Ray Burst, which would
also be a type of supernova. And the GRB was farther away still, at over
13 billion light-years.

I think the difference -- as you indicate in a later message -- is
that GRBs are not known to be supernovae.

A difference that is of considerable practical interest is that
intrinsic luminosities of GRBs are not known even crudely. That
makes cosmological tests using GRBs impossible. Mind you, I'm not
sure luminosities for Type IIn SNe are known well enough to do
cosmology, but at least there's some hope for those.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)

On Jul 10, 3:37*pm, (Steve Willner) wrote:
In article ,
*Yousuf Khan writes:

didn't they announce the oldest, farthest Gamma-Ray Burst, which would
also be a type of supernova. And the GRB was farther away still, at over
13 billion light-years.

I think the difference -- as you indicate in a later message -- is
that GRBs are not known to be supernovae.

A difference that is of considerable practical interest is that
intrinsic luminosities of GRBs are not known even crudely. *That
makes cosmological tests using GRBs impossible. *Mind you, I'm not
sure luminosities for Type IIn SNe are known well enough to do
cosmology, but at least there's some hope for those.

--
Steve Willner * * * * * *Phone 617-495-7123 * *
Cambridge, MA 02138 USA * * * * * * * *
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. *Commercial
email may be sent to your ISP.)

Each new and improved telescope (terrestrial or orbital) will discover
older and further away objects or cosmic events. So what?

What about all the stuff that's nearby and could directly affect us?
(obviously it's not getting 0.1% of the public funded action)

~ BG

On Jul 10, 10:18*am, Yousuf Khan wrote:
Sam Wormley wrote:
Yousuf Khan wrote:
Sam Wormley wrote:
* So did you sort out to your satisfaction the details and differences
* between these observations?

No, enlighten me.

* * Yousuf Khan

*http://www.skyandtelescope.com/commu.../50249452.html

This is just another article about the same story I previously posted in
this thread. What I was asking about was if people had previously
discovered GRB's at 13 billion light-years already, then why are these
people saying that these supernova at around 11 billion light-years are
the farthest out yet? 13 billion beats 11 billion doesn't it?

* * * * Yousuf Khan

What do you expect from a parrot like Sam Wormley?

~ BG

On Jul 10, 1:07*pm, Sam Wormley wrote:
Yousuf Khan wrote:
Sam Wormley wrote:
Yousuf Khan wrote:
Sam Wormley wrote:
* So did you sort out to your satisfaction the details and differences
* between these observations?

No, enlighten me.

* * Yousuf Khan

*http://www.skyandtelescope.com/commu.../50249452.html

This is just another article about the same story I previously posted in
this thread. What I was asking about was if people had previously
discovered GRB's at 13 billion light-years already, then why are these
people saying that these supernova at around 11 billion light-years are
the farthest out yet? 13 billion beats 11 billion doesn't it?

* * Yousuf Khan

* *Have you considered that the GRB might result from something
* *other than a supernova explosion. Did you compare the energy
* *levels?

And those level differences are?

~ BG