Astronomy Project 2007
ECoS Faculty: Mercedes Richards
ECoS Undergraduate Mentor: none
The Supernova as a Cosmic Recycling Center
Supernovae represent some of the largest and most impressive explosions
(called outbursts) in the sky. These events can be produced by single
stars that have created many chemical elements in the core of the star,
and they can also be produced in a binary star system when gas is
transferred from one star to another. When the outburst occurs, the
chemically processed gas is dispersed into the interstellar medium (the
spaces between stars). The newly enriched gas is then recycled to make
new stars; and the cycle continues. Often, the outburst leaves behind a
strange compact object. The very center of the star does not disappear,
but forms a new object called a neutron star. It has a size of about 10
km, and a mass greater than the Sun's mass, so it has a very high
density. One thimbleful of its material would weigh as much as 10
million full sized African elephants. This compact object usually spins
on its axis ten to a hundred times per second, and is called a pulsar.
This rapidly rotating star was believed to be pulsating but we now
understand that the bursts of light occur whenever the rotation axis
points in our direction. As the pulsar slows down over the centuries,
it adds electrons and other charged particles to the interstellar gas
and provides the energy that we see radiating towards us today from all
parts of the supernova remnant. In this project, we will examine the
creation and expansion of a supernova called Cas A, which is located in
the constellation of Cassiopeia.
Powerpoint Presentation