GRB 090423

The cosmos at our fingertips.
Post Reply
saturno2
Commander
Posts: 763
Joined: Wed Jun 29, 2011 10:05 pm

GRB 090423

Post by saturno2 » Fri Nov 09, 2012 11:22 am

GRB 090423 is a object super distant, wich exploded just
630 million years after Big Bang.
The age of Universe 13,700 million of years
Distance of GRB 090423
13,700 - 630 = 13,300 million of light years
Not could to be a supernova, because the stars were in
formation.
What were this object?

User avatar
bystander
Apathetic Retiree
Posts: 21592
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: GRB 090423

Post by bystander » Fri Nov 09, 2012 2:24 pm

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
Chris Peterson
Abominable Snowman
Posts: 18573
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA
Contact:

Re: GRB 090423

Post by Chris Peterson » Fri Nov 09, 2012 2:45 pm

saturno2 wrote:GRB 090423 is a object super distant, wich exploded just
630 million years after Big Bang.
The age of Universe 13,700 million of years
Distance of GRB 090423
13,700 - 630 = 13,300 million of light years
Not could to be a supernova, because the stars were in
formation.
What were this object?
A supernova. There's no reason to think that stars were not present when the Universe was 630 million years old.

BTW, you should be careful with distance calculations, since "distance" has multiple interpretations. The light travel time was 13.04 Gyr, but the comoving radial distance is 30 Gly. The best way to characterize this object is by its redshift, z=8.2, and by its age after the Big Bang, 0.63 Gyr.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

saturno2
Commander
Posts: 763
Joined: Wed Jun 29, 2011 10:05 pm

Re: GRB 090423

Post by saturno2 » Sat Nov 10, 2012 1:04 am

Chris Peterson is right
I have to make a precision
At the time of the explosion of GRB 090423, the distance from
Earth to that object was of 13.3 billion light years.
But Universe is expanding and GRB 090423 away from
Earth.

User avatar
Ann
4725 Å
Posts: 13808
Joined: Sat May 29, 2010 5:33 am

Re: GRB 090423

Post by Ann » Mon Nov 12, 2012 5:37 pm

It is likely that GRB 090423 was a particularly powerful supernova, produced by an extremely massive star. I hope Chris will correct me if I am wrong (which I may well be) but I believe that typical nearby core-collapse supernovae are usually set off by about ten solar masses worth of iron core (or less). In the distant past, when most gamma-ray bursts seem to happen, stars that went supernova may typically have started out with a hundred solar masses or so. Also, these long-ago stars had a different chemical makeup than most of today's stars. The ancient stars were typically metal-poor, which may have resulted in a milder stellar wind. So the stars may have retained more of their atmospheres as well as growing larger cores, making the eventual supernova explosion that much bigger and brighter.

Ann
Color Commentator

Post Reply