M39 - Open Cluster in Cygnus


M39 - Open Cluster in Cygnus

Discovered by Charles Messier in 1764.

Messier 39 (M39, NGC 7092) is a very large but very loose open cluster, situated some 9 degrees east and a bit north of Deneb (Alpha Cygni).

Its distance is only about 800 light years, and it is of intermediate age (estimates between 230 and 300 million years). 30 stars are proven members and contained in a volume of about 7 light years diameter. Its apparent visual brightness of 4.6 magnitudes (e.g., Sky Catalogue 2000.0, Uranometria 2000) corresponds to an absolute magnitude of -2.5, or an intrinsic luminosity of 830 suns. Kenneth Glyn Jones gives its apparent visual brightness as 5.2 mag only, while Don Machholz has estimated it at mag 5.4, in agreement with estimates quoted by Mallas/Kreimer, who also mention D.F. Gray's estimate of a total visual brightness of 6.0 magnitudes.


Imaging Details:

Camera: Apogee U16M with 7-position FW and Gen II Astrodon RGB
Scope: Planewave Instruments 12.5" CDK
Mount: Paramount ME (w MKS5000 upgrade) guided w SBIG ST402ME and Astrodon MMOAG
5 x 5 min for each of RGB

Image acquisition via CCD-Commander and TSX

Bulk of processing in PixInsight with a minor tweak done in PS CC 2019
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Captured June, 2019
Lucknow, Ontario