Reports - 2011

Astronomy Benalla  Dark Sky Site Report - Saturday 2nd July 2011 As our viewing night approached the weather looked ominous, but we were in luck - clouds were absent and, apart from the cold weather, conditions were perfect for observing. With many put off by the cold and the prospect of cloud, a small but determined group assembled at the oval opposite the Benalla racetrack. Our night began with unsuccessful attempts to catch the innermost planet Mercury which lurked low in the western twilight and was probably – because we failed to 'capture' it - below the tree line. Our attention then turned to everyone's favorite planet, Saturn. While the rings are still not very 'open' - they will open further as the year goes on - the sight of them surrounding the planet is never less than stunning. We then tried to 'split' the double star called Porrima, which is the faint star currently very close to Saturn. Unfortunately the two stars which make up Porrima are also very close together and so could not be separated through our telescopes, but as these stars are moving slowly apart from our point of view as they orbit each other, maybe next year! We had more luck with old favorites Alpha Centauri (the brightest of the pointers to Crux the Southern Cress and the closest star system to our Sun) and Acrux, the brightest of the stars in the Southern Cross itself. Both of these stars look like distant car headlights approaching when viewed through a telescope. Turning our telescopes toward the Globular Clusters Omega Centauri and 47 Tucanae, we marveled at these huge balls of stars - about one million in Omega and half a million in 47 Tuc - which revolve around the centre of our galaxy. Both of these huge 'star cities' look like very faint stars to the naked eye and those of our guests who had not seen them before were gob-smacked at the sight of these faint 'stars' through a telescope. Later on, M22 - another globular cluster close to the lid of the teapot in the constellation Sagittarius - also provided stunning views. Next to catch the eye was the Tarantula Nebula - a huge star-forming cloud of gas and dust in the Large Magellanic Cloud. This 'cloud', along with the Small Magellanic Cloud are small galaxies close (in astronomical terms) to our galaxy. If you haven't noticed these 'clouds'  before go outside on a dark clear moonless night sometime soon and look up - along with the Southern Cross they form the three points of a large triangle. Finally, one of the telescopes was turned toward M83, the Southern Whirlpool Galaxy. While pictures of M83 taken through large professional telescopes are breathtaking, it only looks like a faint patch of light through our amateur telescopes. BUT, when you consider how far away it is, it's a 'buzz' that we can see it at all - travelling at three hundred thousand kilometers every second, it takes a ray off light about twenty million years to get to us. So when you look at M83 you're seeing it not as it is now but as it was twenty million years ago. Also viewed later in the evening were a number of the galaxies and nebulae detailed in the viewing notes previously posted for this session. We managed to track down the galaxies Centaurus A, the Sombrero Galaxy (Ml04), NGC5102 and NGC4945. Centaurus A in particular provided pleasing views, with the striking dust lane which seems to split the galaxy in two very prominent. The Lagoon Nebula (M8) and the Triffid nebula(M20) were also found without much trouble, but the Eagle nebula (M16) and the Omega nebula (M17) proved more elusive. While searching for these latter two, what was thought to be the Small Sagittarius Star Cloud was prominent, but as M16 & M17 are quite nearby but remained undetected, this is a puzzle to be resolved at future viewings. There are other galaxies 'up there' to be targeted along with many other objects of interest, so if you are interested, come along to one of our viewing nights and ask for a look!

Pictures from the Hubble Site