I was listening to the May edition of the Jodcast earlier and they were talking to one Carole Mundell who works at the Liverpool Telescope with Gamma Ray Bursts (GRBs).
GRBs are highly energetic, and extremely short-lived flashed of gamma rays that are seen all over the sky. They were first detected by US Military satellites as their signatures looked like nuclear tests. Obviously though, as opposed to a nuclear test, these GRBs happened in the wrong direction (skyward not groundward). Astronomers later became interested when the US Army published its data and since then these events have become the object of study.
GRBs are the most luminous events in the whole universe (so far as we know). They may well be the product of colliding neutron stars or the emmission from jets shooting out of Wolf-Rayet stars as they collapse into black holes created inside of themselves (depicted in image). Whatever they are they are interesting and the astronomy community is out to find them.
The trouble is that they are very short lived. They can last for just milliseconds or at the most a few minutes. This lead scientists and researchers to have to use the height of technology to spot them. NASA’s Swift satellite is just such an example of the kind of thing that could not have been done even a few years ago. Swift was launched in 2004 and watched the sky for the unique signature of a GRB. As soon as it finds one, messages are relayed to the ground within a few seconds and within just two or three minutes (with any luck) a robotic telescope on the Earth (such as the Liverpool Robotic telescope) is turning to look at the source. Whilst Swift can measure the GRB’s spectrum we need to observe these events in other wavelengths to really begin to understand them.
At the same time as the telescopes begin to move around a text message is sent to a whole host of astronomers around the world, alerting them that a burst has occurred. That way if they want they can log in, over the internet, to the telescope system and watch too. I thought that was pretty cool.
You can download the May 2007 edition of The Jodcast right here.