Comet C/2017 T2 Panstarrs

[stevewanstall]

This is the result of  12 x 60s subs in each of luminance, red, green and blue light. There was a 10 sec pause between each image to give more time for the comet to move (requirement for the processing technique). According to the method I was following, the total data time should be under an hour because comets are such dynamic objects. I wanted to have  the stars and comet both in as sharp a view as possible (the comet moves between subs, so with normal processing you end up with a 'streaked' comet)
I was trying to follow Bernard Hubl's method but in the end had to use Deep Sky Stacker and its 'comets and stars' function. 
For Luminance  I produced an image of the comet only.
For R, G and B I produced an image of the comet plus stars. The channels were combined in PS
I stretched both the L and the RGB images in PS and then combined them. 
 The trouble I found with this is that stretching to show  the faint tail with the limited data meant I also developed the streaks left by the stars. My knowledge of PS is not up to removing  broad faint streaks (see the star on the lower right !!)  but leaving the tail.
Anyway, for better or worse:

Comet C/2017 T2 Panstarrs 

Magnitude: 8.6

Phase: 36 °

Distance: 1.6765au

Solar distance: 1.6185au

Velocity: 33.1km/s

Estimated tail length: 0.04au

 

Equipment: Celestron 9.25 XLT at F10,  Skywatcher EQ6 Pro GEM, ZWO 1600MM Pro, ZWO EFW with ZWO LRGB filters, QHY5IIC guide camera on Skywatcher 9 x 50 finderscope, Celestron Focus Motor
Software: Ascom 6, Eqmod, Cartes du Ciel, AstroPhotography Tool, PHD2

Edited May 12, 2020 by stevewanstall