Rosliston Astronomy Group


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Comet Lovejoy 10/1/2015

Andy Mac


Nice clear sky early evening so decided to check for comet again. Couldn't immediately find it so had to head back in to check Sky 6 on the laptop and found that it was higher than I at first thought and formed a right angle triangle with the Pleiades and Betelgeuse. Went back out and found it easily with my 10x42 binoculars and as my eyes became dark adapted I could see it with my naked eyes although using averted vision.


I decided it would be worth imaging it so began to fetch all the gear outside. I was going to use my Canon 400mm f5.6 lens with my Atik CCD camera attached and thought I would not need to guide as my guide camera was still on my skywatcher scope from using it to capture Jupiter the other night, I connected everything up and slewed to a rough alignment with the comet and started to take some images. It was not in the field of view so I started to make some small adjustments to try and bring it into view. As it approached near where I thought it was I noticed that the mount had stopped responding to the controls. I checked the gears and noticed that one of them was moving independently of the shaft. Twenty minutes later after searching for the right size allen key and switching the mount on and off a couple of times I had the thing going again and had started imaging. However as I increased the exposure to 65 seconds I was getting trailing so had to fetch the guide camera out and calibrate it. I managed to get it tracking ok and went inside for dinner.


After dinner saw that the last frame had significant trailing again and noticed that the guide star was nowhere near the alignment grid. Reset everything again and tried 2 and 3 minute and 5 minute exposures and left it running while I went back inside again.


Was going to get some images with colour filters to combine for an LRGB picture but when I went out again it had started to cloud over and although it cleared again there was more cloud on the horizon so decided to pack away.


I have attached 2 images and one video. The images show the comet, one processed with the star trailing option in Deep Sky Stacker, although you can't see any stars in it, and one with the comet tracked and also the stars not trailing. You can see the tail in both images which is quite narrow and streaky. The video is taken with my phone and shows the movement of the comet relative to the star field over a period of about one and a half hours. It was taken of my laptop screen as I scrolled through the images in Deep Sky Stacker that I had just taken. The comet brightens as the shots range from 2 minutes to 5 minutes in exposure.

It is worth getting out to have a look at while it is this bright.


             Andy Mac


Click below to view images and video:

Comet - stars trails

Comet - stars still

Comet - video (MP4)

[Photos/Drawings] [Techniques & Tips] [Pluto Time] [Photographs, drawiings and video by members of RAG after April 2014] [Andy Mac] [Andrew Thornett] [Chris Howe] [Damian] [Dave Jones] [Ed Mann] [Geoff Dryland] [Julian Palmer] [Kenneth Crichton] [Lewis Brailsford] [Nick Cox] [Paul Bertenshaw] [Peter Hill] [Rachel & David Donaldson] [Roger Samworth]