The peculiar nebula Simeis 57.
Simeis 57 (also known as HS 191 and C 191) is a high surface-brightness nebula in the constellation
Cygnus. The distance nor the source of excitation of Simeis 57 are known.
arxiv.org/pdf/astro-ph/0211428v1.pdf
Technical card
Imaging telescope or lens:Teleskop Service TS Photoline 107mm f/6.5 Super-Apo
Imaging camera:ZWO ASI1600MM-Cool
Mount:Astro-Physics Mach-1 GTO CP4
Guiding telescope or lens:Celestron OAG Deluxe
Guiding camera:QHYCCD QHY5III174
Focal reducer:Riccardi Reducer/Flattener 0.75x
Software:Main Sequence Software Seqence Generator Pro, Astro-Physics AAPC, Pleiades Astrophoto PixInsight
Filters:Astrodon HA 36mm – 5nm, Astrodon S-II 36mm – 5nm, Astrodon O-III 36mm – 5nm, Astrodon B Gen.2 E-series 36mm, Astrodon G Gen.2 E-series 36mm, Astrodon R Gen.2 E-series 36mm
Accessories:ZWO EFW, MoonLite NiteCrawler WR30
Resolution: 2272×1714
Dates: Sept. 11, 2018, Sept. 15, 2018, Sept. 19, 2018, Sept. 20, 2018
Frames:
Astrodon B Gen.2 E-series 36mm: 15×5" (gain: 200.00) -20C bin 1×1
Astrodon G Gen.2 E-series 36mm: 15×5" (gain: 200.00) -20C bin 1×1
Astrodon HA 36mm – 5nm: 41×300" (gain: 200.00) -20C bin 1×1
Astrodon O-III 36mm – 5nm: 15×300" (gain: 200.00) -20C bin 1×1
Astrodon R Gen.2 E-series 36mm: 15×5" (gain: 200.00) -20C bin 1×1
Astrodon S-II 36mm – 5nm: 16×300" (gain: 200.00) -20C bin 1×1
Integration: 6.1 hours
Avg. Moon age: 7.04 days
Avg. Moon phase: 48.53%
Astrometry.net job: 2269151
RA center: 304.083 degrees
DEC center: 43.725 degrees
Pixel scale: 2.930 arcsec/pixel
Orientation: 270.000 degrees
Field radius: 1.158 degrees
Data source: Backyard
via Flickr https://flic.kr/p/28L1KYh