NGC 7635, also known as the Bubble Nebula (at the bottom of the picture), is a H II region emission nebula in the constellation Cassiopeia. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow.
NGC 7538, (at the top left of the picture) is located about 9,100 light-years from Earth. It is home to the biggest yet discovered protostar which is about 300 times the size of the Solar System.
(Description credits: Wikipedia)
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: 2328×1760
Dates: Aug. 21, 2017, Oct. 11, 2017, Aug. 11, 2018, Aug. 21, 2018
Frames:
Astrodon B Gen.2 E-series 36mm: 24×10" (gain: 200.00) -20C bin 1×1
Astrodon G Gen.2 E-series 36mm: 21×10" (gain: 200.00) -20C bin 1×1
Astrodon HA 36mm – 5nm: 46×300" (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: 23×10" (gain: 200.00) -20C bin 1×1
Astrodon S-II 36mm – 5nm: 15×300" (gain: 200.00) -20C bin 1×1
Integration: 6.5 hours
Avg. Moon age: 15.17 days
Avg. Moon phase: 35.21%
Astrometry.net job: 2226092
RA center: 349.246 degrees
DEC center: 60.827 degrees
Pixel scale: 2.939 arcsec/pixel
Orientation: 88.476 degrees
Field radius: 1.191 degrees
Locations: Berga Resort, Berga, Barcelona, Spain
Data source: Backyard
via Flickr https://flic.kr/p/2azPaef