Reports - 2011
Astronomy Benalla Dark Sky Site Report - Saturday 5th March 2011
After four months of cloudy or wet viewing nights we finally cracked a full night with a ‘de-darkful’ sky at our new dark
sky viewing site, the Benalla Race Course Cricket Ground. It turned out to be the best conditions we had
encountered for the past year. All four points of the compass had interesting sights available for the six telescopes.
At sundown the solar system’s largest planet Jupiter could just be made out shining through the trees in the red
western sunset. It gave us the last opportunity to view it before it disappears behind the sun to re-appear in the
morning dawn sky late in April, along with its siblings Mars, Mercury & Venus.
While it was still dusk, Wayne pointed his 300mm scope high in the sky to catch the colourful favourite The Great
Nebula of Orion (M42) with its brilliant Trapezium asterism - a grouping of very young hot stars just 1000 light years
away. It is located midway down the sword hanging from Orion’s belt.
While we were waiting for full darkness President Rupe took the visitors for a laser-light conducted tour of the sky
pointing out a few of the various constellations and the major stars:
The Pleiades (M31) or Seven Sisters;
Aldebaran - one of the larger stars in the constellation Taurus, The Bull.
Then, on to the figure of Orion with the red supergiant Betelgeuse at 630 light years distant, up to the saucepan
asterism formed by Orion’s belt and sword, on to the large bright blue/white super-giant star of Rigel (Beta Orionis)
and which is in fact a triple star system with a mass 17 times our Sun.
Our international visitor then wanted to know how to the find south, so it was across to the constellation Crux - the
Southern Cross - and the pointers Rigil Kentauris (Alpha Centauri) and Hadar (Beta Centauri).
This clear dark night opportunity was welcomed by Ed and David as they had both invested in a new style zoom lens
and were eager to check the celestial sights with their Dobsonian telescopes. They were not disappointed with their
outlay when it came to viewing the large globular clusters of Omega Centauri, and 47 Tuc adjacent to the Small
Magellanic Cloud in the south.
All the visitors were anxious to see Saturn and its rings but as it is a late riser this time of the year it wasn’t until after
the break for supper that the crowd favourite was picked up. David found the ringed planet to the usual oohs, ahs
and wows with his 12” Dob. Later Rupe zoomed out with a lower magnification and scanned wide to pick up 4 of its
larger moons Titan, Tethys, Rhea and Dione.
With morning approaching the numbers had thinned out, but lead by Wayne with great skill, found the Crab Nebula
(M1) a supernova remnant of a star that blew up in 1054, then the Bee Hive Cluster (M44) in Cancer and finally the
ruby red star known as DY Crucis, or the Aussie nickname Ruby Crucis, adjacent to Beta Crux before calling it a
night.
The best viewing night we have had, may we have many more!
Rupe Cheetham.