gamma ray burst
gregladen | January 21, 2013Never mind Fresh Water Diatoms hitching a ride on meteors. We've got a possible Gamma Ray Burst in about 774 or 775 CE to talk about. Phil Plait has described the phenomenon which is reported here.
The tl;dr: Extra 14C Beryllium in tree rings laid down at that time had to come from somewhere, and the best explanation at present is a gamma ray burst resulting from two neutron stars melding. This might have been visible; some say that a visible signature would have been in the sky for a while, but maybe not. The gamma ray burst itself would be one of those colorless odorless tasteless…
gregladen | October 29, 2009If you don't know someone's age, over time they may let out clues that tell you when they were born based on what they remember, or things they claim to have done. This can be very inaccurate. My wife said something the other day that would cause anyone to infer that she was at least ten years older than she is, but it turns out the TV show she was referring to came to her home as syndicated re-runs. (My own personal memory of the recently deceased Soupy Sales is a similar example.)The Universe
You can always ask a person his or her age, but you have to infer the age of inanimate objects…
esiegel | March 26, 2008Last week, the brightest gamma-ray burst ever was observed. (See here.) I wanted to know what it was that caused this bright explosion that, despite it being at redshift z=0.94 (or about 7.5 billion light years away), it was visible on Earth with the naked eye!
Well, a scientific paper was written on the observations of this burst, named GRB 080319B, or the second GRB observed on 03/19/08. Let me take you through the highlights. First off, here's what it looked like, in gamma-rays (left) and the afterglow in the optical/UV (right):
When we look from Earth, the faintest objects we can see…
esiegel | March 24, 2008Those of you who keep up with your news may have seen this headline on CNN last week: Star Explodes Halfway Across Universe. What they're talking about is a Gamma-Ray Burst, which was so bright that, despite being 7.5 billion light years (that's 2.3 Gpc) away, it was still visible on Earth with the naked eye. From the article:
The aging star, in a previously unknown galaxy, exploded in a gamma ray burst 7.5 billion light years away, its light finally reaching Earth early Wednesday.
This is the sort of thing that the SWIFT satellite was designed to detect, pinpoint, and then tell Earth-based…