Comet F3 2020 (NEOWISE)
Here’s my best effort at Comet NEOWISE. We got a perfect clear night at last here on Sunday 19/07/20. We took a trip out to Lough Owel near Mullingar for a clear northern horizon and darker skies. One of the best nights under the stars I’ve had, probably the best since camping on Skye last year. We also met some fellow astronomers which was a first. You could see the comet tail spreading across the sky for ages. Well over the length of my outstretched hand. The core has dimmed compared to a week earlier but the tail is much bigger and longer. The comet makes its closest approach on the 23rd of July and the tail should be longest then so get out there and try spot it while you still can. It’s getting dimmer everyday as it moves away from the sun.
I was very pleased to get both tails and the newly formed green coma at the head. The yellow is the dust tail debris being blasted off by the pressure from the suns radiation. The ion tail is formed by ions being dragged from the comet by the suns magnetic field and lit up by the suns light. It points directly towards the sun. The green is caused by C2 escaping the comet and could indicate parts of it have opened up.
After seeing other astrophotographers lauding the benefits of flat frames, I took a full set of calibration frames this time, darks, flats and bias. I should really do it more often. In terms of exposures I used a mix of 16, 2 and 6, 5 minute exposures for a total of 62 minutes integration. Fate was with us and it was during the darkest bit of the summer twilight. Processing in Pixinsight was following Warren Keller's comet guide. Followed up with starnet and the usual stretching. I do have some stacking artefacts and messed up some of my range masks so I’ll need to go back and reprocess in future. The sky was a good bortle 4 possibly bortle 3.
Mount: Skywatcherl Star Adventurer
Tripod: Skywatcher Stainless
Camera: canonuk 600d modified
Telescope: williamoptics Redcat 51
Guiding: zwo mini guidescope and asi 120mm mini
Controlled by ASIair.
Processed in Pixinsight and Lightroom.