NGC6888 The Crescent Nebula

[JohnH]

(Also known as the Dividing Cell Nebula)

Taken on 10th and 17th October - 2 hours 45 mins in total

Luminance Ha, Chrominance (Ha+R)GB. I also took L subframes but they suffered too much from a combination of cloud and dew to be used. I almost had to discard the Green subs for the same reason but they were just usable.

Telescope: Sharpstar 15028 HNT ( 418mm focal length f2.8 )
Mount: iOptron CEM 25P
Imaging Camera: ZWO ASI1600M Pro at -15C
Control:ASIAir Pro
Processing: Pixinsight
Location: Bromley - Bortle 7 to 8.

The nebula is about 4,700 Ly distant. Visual Magnitude 7.4 and approximately 20 x 10 arcmins. It sits in the band of the Milky Way and so I have worked very hard to minimise the star-field.

The bright star bottom left is P Cygni, visual magnitude +4.78 and a very rare "blue variable" (not very blue in my image!) and is one of the brightest stars in the Milky Way. Not surprisingly therefore it is also one of the most distant stars visible to the naked eye.

I do quite like the Hydrogen clouds surrounding the nebula. The stars are a little less round than I would like. I am too impatient, I need to spend more time getting channel data!

This is my attempt to get back to imaging since I started with Long Covid which is even stopping me coming to meetings at the moment.

Regards,

John

[Roberto]

Very nice John!  Lovely star colours.

Roberto

[The Thing]

Nice one John, keep it up.

[Carole]

Great result John and so glad to see you imaging again after your health issues, I hope seeing this image means you are finally starting to feel a little better.

Carole

[JohnH]

Thanks all. Just hope that I can keep getting better results.

I have now discovered how to allow for backlash on the focuser, this seems to make may stars about 10% smaller.

Regards,

John

[Carole]

I had forgotten about your dodgy stars issue.  Certainly looks a lot better. 

Carole