This is the lovely composite Hubble space telescope picture that is going around, showing the debris of a supernova – a star’s explosion. This is Cassiopeia A, and the explosion happened in 1680 AD, our time. See HST’s website for more on this , and discussion on the Bad Astronomy Blog.
In other supernova news, there’s a lot of news today (Wed) about a new supernova explosion, recorded this year (2006). This particular event is highly significant since astronomers were able to watch most of the entire event in real time. The thing that signalled that something was about to happen was a (relatively mild) gamma ray burst (GRB060218 – it was seen in Feb. 18th) picked up by the Swift telescope. After the burst (really it was an X-ray flash… a GRB’s younger sibling, as it were) faded, the star exploded -essentially on camera.
Quote from an AFP (via Yahoo News) article:
“Usually these events are not detected until after the supernova has brightened substantially in the optical wavelength, many days after the initial explosion,” said Keith Mason, chief executive of Britain’s Particle Physics and Astronomy Research Council (PPARC), which operates an ultra-violet/optical telescope aboard Swift.
“But on this occasion we were able to study the remarkable event in all its glory, from the very beginning.”