Sh2-115, Emission Nebula
Sh2-115 is an extensive, faint emission nebula located in the constellation Cygnus, approximately two and a half degrees northwest of Deneb and about 7,500–7,800 light-years away. It contains the young open cluster Berkeley 90, whose several massive stars ionize and shape the surrounding gas through their intense ultraviolet radiation and stellar winds. The nebula has a complex morphology with filaments, cavities, ionization fronts, and dark clouds. The small planetary nebula Abell 71 (PK 085+04.1), also catalogued as Sh2-116, is visible in the lower-right part of the image; it lies in the foreground and is not physically associated with Sh2-115. The image was processed in narrowband using an SHO combination and the Hubble palette. PK 085+04.1, also known as Abell 71 or Sh2-116, lies very close by in the same field of view in Cygnus, at an estimated distance of between 2,400 and 3,100 light-years from Earth. For many years it was classified as a planetary nebula with an almost circular, nearly spherical morphology. More recent astrophysical research, however, has shown that this appearance conceals a much more complex ellipsoidal structure that interacts closely with the Sh2-115 hydrogen-emission region. Its proximity to and physical overlap with the surrounding interstellar medium continue to fuel debate among astronomers over whether it is purely an isolated planetary nebula or a star-forming region with unusual characteristics.
General information
- Constellation
- Cygnus
- Category
- Nebulae
- Date
- 5 July 2026
Capture
- Total time
- 5h 45min
- Subframes
- 300s (Ha: 33x, OIII: 20x, SII: 16x) bin1
- Gain / Offset
- 125 / 30
- Calibration
- 30 flat frames, 30 dark-flat frames and 40 library dark frames per sessió and filtre, without bias frames
Equipment
- Telescope
- TS102ED f/5.6
- Camera
- ASI294MM at -10ºC
- Filters
- Ha, OIII and SII Astronomik, 6 nm
- Mount
- Sky Watcher Wave 150i
- Guiding
- PHD2, Guide scope 60mm/f4 + ASI220MM + PegasusAstro UCH + PPBMicro
- Focuser
- ZWO EAF
- Filter wheel
- ZWO EFW 7pos
Processing and environment
- Processing
- Stacked and post-processed with PixInsight 1.9.4
- Acquisition
- NINA
- Location
- l'Ampolla
- Sky
- Bortle 4
Annual visibility
178 days per year above +30° at 00:00 UTC from 41° N, 1.5° E.