Abell 85 aka CTB 1

[Jedi2014]

Hi,

in the last 3 weeks there hasn't been much going on here. I had 5 nights with longer cloud gaps in which I could collect sparse photons for a rather difficult supernova remnant. After 14 hours of difficult HAOIII and RGB (thereof several hours at moonlight) I had almost given up, when an friend of mine (Juergen Beisser from Lilienthal near Bremen) suddenly rubbed his just finished bicolor version of the same object under my nose. He had run in a total of 9.5 hours. Both my 14 hours and Juergen's 9.5 hours for themselves resulted in a "usable picture", but I wouldn't exactly call it an eye opener. We agreed to merge our data, which I did. The version we show here is just ONE of many possible versions that could be obtained from the collected data. In principle, it is a composite of bicolor and HaRGB, whereby I tried to preserve the RGB impression and not focus on the H-Alpha. With more Ha, the background would be much more red, but this would steal the show from the bubble.

Abell 85, aka CTB 1 is a large supernova remnant (SNR) located in Cassiopeia. The southern portion of the supernova remnant bubble also made it to Lynds bright nebula catalog as LBN 576. Originally catalogued by George Abell as a planetary nebula, it soon became evident that it was actually a SNR. It was also recognized as a radio source and acquired the alternative designation CTB 1. The right side of the field includes a small reflection nebulae (GN 23.50.6.03), which is not clearly visible in this image, and a small possible planetary nebula (We 2-262).
Abell 85 has relatively weak [OIII] and H-Beta emission compared to the "traditional" supernova-remnant lines of H-alpha, [NII], and [SII]. In fact, this object is often considered as one of the most challenging for visual observation and remains a big challenge for CCD photography. North is up in this image.

More on my website: http://www.spaceimages.de/en/astrophotos/nebula/abell-85-aka-ctb1
or http://www.astrobin.com/320277/

Juergens image individually: http://www.astrobin.com/319273/

Annotation:

 

Pure RGB data without any processing except DBE, streching and scaling:

 

Cheers

Jens

[Allinthehead]

That's a beauty Jens

[wimvb]

Another great image, Jens.

130+ likes on astrobin in one day. That must become an iotd.

[swag72]

Nice one everything Jens..... well done to you and Jürgen on this ?? You've kept great star colour and remnant itself stands out well. I did this myself years ago ..... I really must go back and do it again some time ?

[Jedi2014]

Thanks a lot for the nice comments. This one is a tough target, well... before I look at it again, it's going to take years.

[MartinB]

The OIII crescent is wonderful!

[wimvb]

Congratulations on the IotD on astrobin

[Jedi2014]

Hi Wim,

as you anticipated :-)
you don't know the lottery numbers for the weekend, do you?

[wimvb]

1 hour ago, Jedi2014 said:

Hi Wim,

as you anticipated :-)
you don't know the lottery numbers for the weekend, do you?

Which lottery? There are so many. 

I wish I knew them. But predicting your image as an iotd was a no-brainer. Imo, it could become an APOD as well. It's that good.

And of course, my congratulations to Jürgen Beisser also, as this was a collaboration.

[Jedi2014]

Thank you Wim ?