|
Supernovae |
|
|
Supernovae are stupendous explosions that destroy an entire star. The "nova" ("new") part of their name is because they are mostly seen as `new' stars appearing suddenly where no star was seen before because of their sudden increase in brightness. They can, for a few days, rival the combined light output of all the rest of the stars in the galaxy.
The last supernova to be seen in our galaxy was observed by Kepler in 1604. The brightest since then was supernova 1987A in the Large Magellanic Cloud, a small satellite galaxy to the Milky Way visible in the southern hemisphere. The brightest supernova in the northern sky for 20 years is supernova 1993J, in the galaxy M81, first observed on March 26, 1993.
Supernovae can be divided into two general classes: Type I and Type II. The type II supernovae involve the collapse of a stellar core and need not be in a binary system. It is thought that the type I supernovae generally involve accretion in binary systems. The adjacent Hubble Space Telescope image shows the red supergiant star Betelgeuse, which is about 600 light years away in the constellation Orion (Ref). (This image represents the first time that the disk of a star other than the Sun has been resolved directly.) It is near the end of its life, and will likely explode as a type II supernova before long.
Some supernova links:
Next
Back
Top
Home
Help