Abell 61 is pretty faint and pretty ancient planetary nebula in Cygnus. It is located somewhere aroud 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.
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