46P/Wirtanen, 2018-12-10, Manche, France

[The Thing]

46P/Wirtanen is putting on a show in Cetus just now, got a gap in the clouds but had to shut the roof half way through due to a shower . I got a good look though my 20x80 binos as well. To give an idea of size, field of view of the image is a bit less than 1.6x1.2 degrees (due to image cropping) so the coma is getting on for the size of the full moon.

There is a quite bright background in the DSS stack due to passing water vapour so I've set the black level quite high, the was more extensive in binoculars. I'm not sure why the stars all seem to have the same colour given the nice green hue of the comet coma. Oh for a nice clear night!

55 subs x 30s @Gain 390(max) and -20C
Image date, time and location:   2018-12-10 Manche, France
Telescope aperture and focal ratio:   TS1506UNC f4, TS Komakorr
Camera and filters used:   ZWO ASI294MC Pro, UV Photo filter
Processing applied:   DSS 4.x, Startools, GIMP




46P/Wirtanen
Magnitude: 9.0
Phase: 32 °
Distance: 0.0845au
Solar distance: 1.0557au
Velocity: 37.3km/s
Estimated tail length: 0.02au
Date: 2018-12-10 23h06m48s
ref: 4/2018-12-07
Hourly motion: 08'43.0" PA:25° dRA:14.57s dDec:07'55.2"
Apparent RA: 03h18m48.44s DE:+02°18'04.2"

Visibility for your observatory:
Blainville-sur-Mer 2018-12-10 23h06m48s ( CET )
Universal Time: 2018-12-10T22:06:48 JD=2458463.42138
Azimuth: 179°59'29"
Altitude: +43°15'05.8"
Airmass: 1.5
Rise:Local horizon 19h05m40s Azimuth:111°42'
Transit:23h06m48s +43°15'
Set:Local horizon 03h05m51s

[ApophisAstros]

Nice Duncan, one question , moving that fast how does it move so little in relation to stars , in your image?
Roger

[Fay]

Very nice capture Duncan.......

[The Thing]

Hi Roger,

The answer is DSS comet stacking function set so it does a stack for the stars and a stack for the comet and combines them. Works most of the time!

[Carole]

Well done Duncan, and well done getting the comet stacking mode to function in DSS, I found it worked sometimes but not every time.  Gave up in the end.

Carole

[The Thing]

Thanks Fay. There's another one around at the moment. If the clouds clear I might give that a go.

[MarkS]

Very nice.  That's an excellent capture!!

Mark