Thursday, November 27, 2008

Rev. Robert Evans - Star Hunter

Like our Sun, the stars we see in the evening sky are burning balls of gas. Eventually, every star will exhaust its fuel and die. The manner in which a star will end its life depends on a number of factors, but it is the exploding stars (or supernovae) that are most spectacular. When a star becomes a supernova the result is a very bright illumination for a period of weeks or even months following the event. Stars that were so distant they could not be discerned with even the most powerful of Earth-based telescopes suddenly appear when they become supernova.

In the 1980s this was an area of interest for astronomer who wanted to understand what happened to stars that exploded in this manner. Their primary interest was in finding a supernova and studying its light characteristics in the weeks following the explosion. This is where two Australian amateur astronomers - Gregg Thompson and Rev. Robert Evans - played their part using nothing more than a 10-inch telescope, hand drawn sketches of star-fields and the dark skies of rural Australia.

Between 1981 and 2007, Rev. Robert Evans (a Uniting Church Minister), was credited with discovering 41 supernovae through visual observation. Professional astronomers would photograph areas of the night sky with their large telescopes and compare the images over time for the appearance of a supernova. Robert Evans on the other hand would visually examine various galaxies, thought to be potential candidates for supernova, and compare them night after night, cross-checking them against the star maps prepared by Gregg Thompson.

His first discovery was Supernova SN 1981A in the galaxy NGC 1532 in late February 1981, while holidaying on the north coast of New South Wales. He went on to discover another 40 supernovae visually, another five on photographic film, as well as the Comet Evans Drinkwater. To this day he is credited with discovering more supernovae visually than anyone else.

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