|Designation:||Caldwell 109, NGC 3195.|
|Apparent size:||40 arc-sec.|
|Distance:||6,500 light years.|
|Exposure:||29 x 3 min = 56 min.|
|Field of View:||24.4 x 24.4 arcmin; up is 305 degrees E of N.|
I recently added a 2x powermate to my toolbox, specifically to assist in capturing objects like this.
The outer envelope of the gas nebula – a reddish colour in my image – is expanding at 40 km per second.
Its central star, a mag +15.3 white dwarf, is difficult to pick out amid the swirling nebulosity.
In “Annals of the Deep Sky“, the authors Kanipe and Webb describe: “The overall impression is looking down into an outer cylinder filled with equal parts light and shadow, stirred gently about a central luminary”. It’s difficult to tell whether it really is a cylinder or more spherical in nature.
It’s been a difficult year so far. I keep in touch with my friends from Macarthur Astronomical Society via a monthly Zoom meeting but I’ve barely left the house since February and have had no chance of going on a field night with them since November.
This, in turn, has encouraged me to spend more telescope time alone at home. Weather and Moon permitting, I have managed twenty-five outdoor sessions so far this year.
The weather has been lousy this month, which has given me a bit of time to focus on three technical issues, which are: (i) the failure of my ‘flat images’ to remove dust blobs from my pictures; (ii) why the blobs are there at all; and (iii) the need to leverage a greater accuracy from my EQ6-R mount now that my field of view has dropped from 1.6 square degrees to 0.4 square degrees.
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor.|
|840 mm focal length @ f/7 with field flattener.|
|Baader L-Booster UHC-S light pollution filter 2458276 +2x Powermate|
|SkyWatcher EQ6-R Pro mount.|
|Camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx)|
|ZWO ASI120 guide camera, using PHD2 software.|