Tonight’s observations

For the first time in far too long, the sky has actually cleared, so I thought I’d take my cameras and telescopes out for a walk, just to remind them what life outside the cupboard looks like.

As evenning fell, I trained the Celestron 130 SLT on Venus and enjoyed the view through the 12, 9 and 4mm eyepieces. The disc is pretty large and shapely now. I then decided to try out my new T-ring adaptor, which allows me to screw my Nikon f55 onto the T-ring I normally use with the CCD and then slot the entire lot into the eyepiece hole. The SLT isn’t very good for afocal photography, the focusing rack never goes in far enough, but the T-ring I have comes with an eyepiece bed and that has no problems focusing. Well, none except that screwing and slotting everything in place takes longer than Venus decided to stay above the roof of the neighbour’s house for…

About eleven o’clock I wandered out of the house and down the road, watching for signs of Noctilucent Clouds and also establishing the best place for a low northern horizon. It turned out to be the lane I normally use for a low northern horizon… I’ll eventually convince myself. I walked back to the house and found I couldn’t get in. My father had gone to bed and forgetting a clear night normally means his astronomer son goes outside occasionally, he always locks the door. The backdoor was also shut, so I scurried back to the front to ring the doorbell. As I rounded the side of the courtyard, I noticed two stars where only Arcturus should be. It was an Iridium flare, probably Iridium 63 going off ten minutes earlier than scheduled at 23:14. The flare ended with the satellite just a breadth away from Arcturus itself.

Then I woke up dad and got inside.

Later on and with my father carefully packed away for the night, I headed out again, this time armed with my oldest telescope, the Greenkat 60mm spotting scope on one of my grandfather’s camera tripods. I returned to the lane and spent some time slowly scanning the sky with it. I found I wasn’t there alone as my kitten Dione had decided now was a good time to accompany me for a walk. She mewed loudly whenever I dared take my eyes off her, but eventually became interested with things crawling by a nearby garden door.

It took some time, but eventually, I coaxed the kitten home and returned to the lane around a quarter to one. I found the comet after careful focusing and scouring the area suggested by Heavens Above and their finder chart. On the magnified chart, there is an asterism (group of stars) that looks to me like a squashed little dipper. Through the Greenkat, only the star at the end of the handle was visible along with the comet coma and that itself was only visible as a blurry star that refused to attain sharp focus when all around it were fine. I had found Comet C/2009 R1 McNaught, lying between two thirds and three quarters of the way down from the topmost bright eastern star in Perseus to the bottom-most eastern star. It had taken some time and some luck, but it was there.

I went home and exchanged the Greenkat for the Celestron. Returning, I found attaining the comet a lot easier now I was sure where everything was. The comet had moved a little as the Earth rotated, but it was shifting to the East rather than the West – due to its being under the pole star and so sweeping round the parts of the circle hidden to us at lower declinations. The view through the 12mm eyepiece wasn’t tremendous, but it did push the thing I could see from ‘odd fuzzy thing’ to ‘comet coma’. The telescope’s increased aperture (130mm as opposed to 60mm) and lack of light absorbing erecting lenses meant more of the coma was visible along with the background field stars – including that little dipper. Now in the north at this time, we have all night twilight and what that means for astronomers is that the contrast between the things we look at and the night sky plummets. This means the magnitude seven comet McNaught was inferior at the eyepiece to the magnitude nine comet Lulin, the last one I looked at. It didn’t help that McNaught is rather small compared to the very extended Lulin. This comet will brighten, but it races against the twilight, which will also brighten with the approaching solstice. By the time it is getting dark again, the comet will have headed for the horizon. By the time it is at its brightest and the twilight has been reduced from present levels, it will be gone.

And there were no NLCs to report this morning either, though I did see a rather nice contrail lit up and slowly drifting overhead.

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