A stellar postmortem January 6, 2009Posted by Sarah in science.
Tags: astronomy, chandra, nasa, space, supernova, x-ray
The 213th American Astronomical Society meeting started this week over in Long Beach and there’s lots of cool astronomy to report!
Take a look at this amazing video of supernova remnant Cassiopeia A, compiled from X-ray observations with space observatory Chandra, spanning 8 years. Cas A was one of Chandra’s very first targets, and by watching the images evolve over time scientists have been able to determine the expansion velocity of the hot expanding blast wave.
Travelling at 11 million miles per hour, if you can believe it, the shock front is actually travelling much more slowly than they expected! Interestingly, the astronomers think this means that much more of the energy of the supernova is being blasted out in the form of high-energy protons and ions – the kind of particles that bombard the Earth’s atmosphere as high energy cosmic rays.
Several scenarios can cause supernovae explosions but they alwasy signal the death of a massive star and the birth of a neutron star or black hole. They are some of the most violent events to take place in the Universe, really fascinating to study. They are the source of all heavy elements in the Universe in some shape or form, so in fact they are the reason life is possible here on Earth, or indeed that Earth was formed in the first place. The little white dot shown at the centre of the image is the hot neutron star, left to cool at the centre of the turbulent expanding nebula.