Abell 61

Abell 61 is pretty faint and pretty ancient planetary nebula in Cygnus. It is located somewhere around 4,500 light years away and its age is estimated to 22,000 years. Central star apparent brightness is 17mag, and its surface temperature is over 60,000 K. Apparent diameter of Abell 61 is about 3.3 arc minutes, so it is similar size as famous M97 Owl nebula. But Abell 61 is about 100 times fainter. 

I made image below over six different nights. I collected narrowband photons with Moon present. Additionally LRGB signal was captured over one night. Under my suburban sky LRGB signal contained very low amount of nebula itself, that’s why I added some significant amount of hydrogen alpha and oxygen iii narrowband frames. Telescope used was Meade ACF 10″, camera QHY163M and mount EQ6. Total exposure time was 2 hours for LRGB filters, 2.5 hours for Oiii and 3.5 hours for Ha.┬áThis is quite decent amount of data, but the data quality was far from perfect. The Moon was present in the sky, and Abell 61 is actually quite faint, so significant noise was present even at narrowband images.

Abell 61
Abell 61 old planetary nebula in Cygnus

Large version https://astrojolo.com/wp-content/uploads/2018/06/2018-05-20-A61.jpg

Clear skies!

Image technical data: 

Date: 05,06,14,17,18,19.05.2018 
Location: Nieborowice, Poland 
Telescope: Meade ACF 10" 
Corrector: AP CCDT67 
Camera: QHY163M 
Mount: SW EQ6 
Guiding: SW 80/400 + ASI290MM 
Exposure: Ha 40x5, Oiii 30x5, LRGB 40:30:20:30x1 minutes 
Conditions: seeing average-good, transparency average, Moon present

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