erick
19-11-2007, 10:52 AM
Sometimes I try the silliest things. I reckoned I'd have a shot at viewing this fella from Melbourne. Yeah it's low, real low, so all I need is some elevation - right?
Found a spot up in the Dandenongs at 420m where I could look to the North. There are mountains to the North, but there was a gap in the ranges exactly to the North of my observing location and I calculated that the comet should transit that gap, or a little higher, for around 30 min at 1am.
So there I was, last night, set up with my 20x80s from 12:30am, looking at .......... well cloud to start with. But that finally cleared to reveal........... hellish skyglow from Melbourne! Even the Pleiades were not easy to spot naked eye and they were to be my direction marker. But through the 20x80s, no problem.
To cut to the answer, I didn't observe Comet 17P/Holmes, but then I hardly observed anything lower than delta Persei at around 3-4 deg. The dead giveaway was that alpha Persei (Mirphak) could not be seen (around 1 deg elevation!!!), transiting the gap, or even higher, I thought. The comet should be at that elevation or a little higher.
I've attached a plot from Stellarium. The star under the cursor is delta Persei. The straight white line is approximately 0 deg elevation. With the extra height, this may have been a bit above the horizon (Stellarium doesn't seem to adjust when I change the elevation - it's too painful a piece of software to try and go to 2000m to test it! Individual clicks on a button are required to slowly add 10m at a time!) The wiggly line is the elevation below which I could not see stars. Red circle/cross - approx position of the comet.
However, three clues:- 1) By 2:18 as I headed home, the Moon was a deep dark red colour at about 1 deg. 2) We have had fires in Victoria in the direction of the prevailing wind last night. 3) This morning as I drove to work there was a very obvious band of smoke/pollution up to about 10 deg elevation.
I reckon if I had clean air I might pick it out! Am I stupid enough to stay up and try again? Who knows!
:stupid:
Found a spot up in the Dandenongs at 420m where I could look to the North. There are mountains to the North, but there was a gap in the ranges exactly to the North of my observing location and I calculated that the comet should transit that gap, or a little higher, for around 30 min at 1am.
So there I was, last night, set up with my 20x80s from 12:30am, looking at .......... well cloud to start with. But that finally cleared to reveal........... hellish skyglow from Melbourne! Even the Pleiades were not easy to spot naked eye and they were to be my direction marker. But through the 20x80s, no problem.
To cut to the answer, I didn't observe Comet 17P/Holmes, but then I hardly observed anything lower than delta Persei at around 3-4 deg. The dead giveaway was that alpha Persei (Mirphak) could not be seen (around 1 deg elevation!!!), transiting the gap, or even higher, I thought. The comet should be at that elevation or a little higher.
I've attached a plot from Stellarium. The star under the cursor is delta Persei. The straight white line is approximately 0 deg elevation. With the extra height, this may have been a bit above the horizon (Stellarium doesn't seem to adjust when I change the elevation - it's too painful a piece of software to try and go to 2000m to test it! Individual clicks on a button are required to slowly add 10m at a time!) The wiggly line is the elevation below which I could not see stars. Red circle/cross - approx position of the comet.
However, three clues:- 1) By 2:18 as I headed home, the Moon was a deep dark red colour at about 1 deg. 2) We have had fires in Victoria in the direction of the prevailing wind last night. 3) This morning as I drove to work there was a very obvious band of smoke/pollution up to about 10 deg elevation.
I reckon if I had clean air I might pick it out! Am I stupid enough to stay up and try again? Who knows!
:stupid: