Abell 21, The Medusa Nebula in HOO

[umasscrew39]

Following many frustrating evenings of poor weather, I at least gathered enough data to come up with an image of this planetary nebula. The Medusa (Abell 21), discovered relatively recently in 1955 by University of California astronomer George O. Abell, classified it as an old planetary nebula. The nebula is large but its surface brightness is very low, with surface magnitudes of between +15.99 and +25 reported. Thus, it can be a challenge under Bortle 6 skies, especially with a lot of "below average seeing" nights which is what you are viewing here. I tried various HOO combinations with PixelMath to bring more of the OIII out but was not that successful.

[Greenman]

Unusual subject and you picked a hard one, lovely remnant - thanks for sharing.

[MariusD69]

Wonderful image! Great work!

[jthommes]

Great looking image Bruce.

[Ylem]

Lookin' Good Bruce!
Very nice

[messier 111]

well done , thx

[STEVE333]

Pretty image Bruce. That may be the dimmest nebula I've seen presented here (maybe the Squid?).

The link below is to a tutorial to help bring out the blue in NB images. Maybe it will help?

https://www.youtube.com/watch?v=5M3zB7-Llhw

Good luck.

Steve

[BABOafrica]

Such a beautiful image of a very difficult target.

BABO

[umasscrew39]

Thanks to all for the compliments. This was indeed a tough challenge, especially given underwhelming amount of good seeing for the OIII data in addition to the nature of the nebula itself being extremely dull. That also probably explains the lack of folks imaging it but it was fun to to do despite the nightly hair-pulling!

Steve- thanks for the video. I tried it and it was a slight improvement but I think the OIII data is just overwhelmed by Ha. I will surely try it on other DSOs.

[Juno16]

Amazing work on this image Bruce. Beautiful job!

[Gmetric]

Beautiful image and, as has been mentioned, a tough target. Very well done

[ic_1101]

Excellent capture on this dim target!