From: LARRY KLAES (ljk4_at_msn.com)
Date: Mon Jul 26 2004 - 05:25:09 PDT
http://www.theaustralian.news.com.au/common/story_page/0,5744,10247650%255E29098,00.html Reverend is world supernovae sleuth
>From AFP
There, for many years, this 67-year-old retired clergyman of Australia's Uniting Church has sat by his telescope on a swivelling wooden mount gazing towards the heavens for hours on end as though in commune with his maker.
But Evans looks not for heavenly guidance: he is digging deep into the past, for a new twinkle among billions of stars that signals that rarest of astronomical phenomena -- the supernova, giant stars in their death throes exploding with spectacular power.
Unknown to the public, Evans is himself a phenomenon, a star of the international astronomical community in which his 40cm backyard telescope and an astonishing memory have made him -- by a large margin -- the world champion visual finder of supernovae.
"They explode with combined power of a trillion hydrogen bombs and if they were any closer -- say, a few hundred light years away -- they would wipe out life on earth," Evans told AFP at his home in the Blue Mountains 80km west of Sydney.
"Within recent geological times they have all been thousands or millions of light years away, too far to do any damage, although there has been speculation it was a supernova that caused the contamination of the earth that destroyed the dinosaurs," he said.
Apart from being a threat to humanity -- although an unlikely one -- Evans said supernovae have become the subject of study by an entire industry of professional astronomers, as an important indicator of the expanding nature of the universe.
Some scientists believe they send a shower of mineral atoms into the Universe that may have been a major dynamic in the creation of life on earth.
"Supernovae explosions produce and distribute the chemical elements that make up everything in the visible Universe -- especially life," one international expert, Dr Stephen Smart of Cambridge University, wrote recently.
"It is essential that we know what type of stars produce these building blocks if we are to understand our origins."
Few have contributed more to this knowledge than Evans.
Since the late 1980s computers have made the job easier, but since supernovae were first hypothesised in the 1930s by Bulgarian-born US-based astrophysicist Fritz Zwicky, about 80 have been discovered visually by astronomers around the world.
Of these, 39 were found by Evans and recorded by the International Astronomical Union (IAU).
For most of the 24 years since he began his study, Evans had the advantage of being the only amateur astronomer in the southern hemisphere, with the sky to himself as he searched for supernovae, while the others were all in the northern hemisphere.
But his biggest advantage is a memory for star patterns which has been likened to that of an autistic savant -- which Evans is not.
He is able to scan the night sky at the rate of up to 400 galaxies containing literally billions of stars in any one session, memorising the star patterns so that he can then spot a new one when it appears. Their only distinguishing feature is that they occupy a point in the galaxy that was previously empty.
In his new book, "A Short History of Nearly Everything", American writer Bill Bryson devotes a chapter to Evans' achievement, describing it thus: "To understand what a feat this is, imagine a standard dining-room table covered in a black cloth and throwing a handful of salt across it. The scattered grains can be thought of as a galaxy. Now imagine fifteen hundred tables like the first one -- enough to make a single line two miles long -- each with a random array of salt across it. Now add one grain of salt to any table and let Bob Evans walk among them. At a glance he will spot it. The grain of salt is the supernova."
Evans spotted four supernovae last year, including one in June officially registered as SN 2003gd in the nearby galaxy M-74 in the constellation of Pisces.
He estimated it was some 25 to 30 million light years away, meaning that the explosion he witnessed happened 25-30 million years ago -- much too far away to be a threat to earth.
It was only the third supernova to have been previously observed as a star.
Although invisible to Evans' telescope, it had been imaged less than a year earlier by NASA's Hubble Telescope.
The discovery, recorded in the January 23, 2004, issue of Science, confirmed for the first time the long-held theory that some of the most massive stars in the universe end their lives in violent supernova explosions.
So has this remarkable journey of scientific discovery changed Evans' beliefs?
"It has strengthened my belief in God," he said. "Star gazing is simply a hobby, but it is understanding as far as seeing things that show the glory of God and, of course, the Christian understands where beauty comes from. It doesn't happen by chance."
This archive was generated by hypermail 2.1.6
: Mon Jul 26 2004 - 05:33:58 PDT
July 26, 2004
AS the rest of Australia sleeps, the Reverend Robert Evans rises quietly to avoid waking his wife and moves to the patio at the back of his home.