Natural Phenomenon [Supernova]

Supernovae are exploding stars. They represent the very final stages of evolution for some stars. Supernovae, as celestial events, are huge releases of tremendous energy, as the star ceases to exist, with about 1020 times as much energy produced in the supernova explosion as our Sun releases every second. Our Sun, fortunately, will not end its life as a supernova.

Currently, supernovae are only seen in galaxies other than the Milky Way. We know that supernovae have occurred in our Galaxy in the past, since both Tycho Brahe and his protege, Johannes Kepler, discovered bright supernovae occurring in the Milky Way in 1572 and 1604, respectively.

And, the Chinese, and others, have records of a "guest star" occurring in 1054 in the present constellation Taurus. Today, we see remnants of all three supernovae, which appear as expanding clouds of gas, where each was originally discovered. However, no supernova has been seen in our Galaxy since Kepler's.

Supernovae, when they are discovered, are designated by the year in which they are discovered, and the order in which they are discovered during that year, by using members of the alphabet. For instance, the fourth supernova discovered this last year was named SN 1998D, which occurred in the galaxy NGC 5440.

The brightest supernova since Kepler's supernova was discovered on February 23, 1987, in the nearby galaxy, the Large Magellanic Cloud (LMC). This supernova was easily seen with the naked eye throughout 1987 in the Southern Hemisphere. This supernova was named SN 1987A. This supernova is still being observed by a number of telescopes, particularly, the Hubble Space Telescope. Another bright recent supernova, observable from the Northern Hemisphere, was SN 1993J in the galaxy Messier 81 (M81).

As of 1998 January 1, 1270 supernovae have been discovered since supernovae first really began to be catalogued in 1885, when a supernova went off in the nearby Andromeda galaxy.