Total Integration from Nov 02, Nov 5, Nov 6, Nov 7, Nov 8, Nov 10, Nov 11, Nov 12, Nov 13, Nov 14, Nov 15, Nov 16
- Antlia 4.5 nm, H-Alpha 121 x 300 seconds, Gain 121, Offset 10, Bin 2x2 (10hrs 5min)
- Antlia 4.5 nm, OIII 458 x 300 seconds, Gain 121, Offset 10, Bin 2x2 (38hrs 10min)

People have been taking photographs of Andromeda Galaxy for over 130 years (the first photo was Dec 29, 1888 by Isaac Roberts)
But only recently did amateur astronomers, Xavier Strottner, Marcel Drechsler, and Yann Sainty discover an OIII emission arc right next to it.
They used over 100 hours of data to capture and bring out this ultra-faint nebula, never seen before.
I was pleasantly surprised that I could just barely reveal this new discovery with "only" 48 hours of data, from my home:

This is the image by the discoverers, Strottner, Drechsler, and Sainty:

https://www.astrobin.com/1d8ivk/H/