PN Abell 21  -  Medusa Nebula

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Object data of PN Abell21

Object type: Planetary nebula
Size: 12'
Magnitude: 10.2 mag
Constellation: Gem
Distance: 1,500 Ly
Notes: Abell 21, the Medusa Nebula is an old planetary nebula in constellation Gemini. Its distance is estimated to be about 1,500 light years.

Exposure data

Date: 2017-02-14 + 2017-02-15 + 2017-02-16
Location: Nussbach / Austria (400m)
Telescope: 12" Newtonian telescope (f=1120mm)
Camera: QSI 660wsg-8 with Astrodon filters
Binning: L 1x1 / RGB 1x1 / Ha 5nm 1x1 / [OIII] 3nm 1x1
Mount: ASA DDM85
Exposure time: L 42x2min / RGB 15x2min each / Ha 34x8min / [OIII] 36x8min
Exposure time total: 12h 14min
Notes: Image acquisition in 3 nights with bright moon