M 39 (NGC 7092) Open Cluster in Cygnus

Located at: RA 21 hours 32 minutes 12 seconds, Dec +48 degrees 27 minutes 00 seconds

Size: 31' Magnitude: 4.6 Class: III 2 m

North is up

West to the right

Telescope:

8" f5 Newtonian reflector

Camera:

ST-8XME, self-guided, binned 1x1, temp -15 c & -20c, camera control MaxIm DL 4.56

Image:

 Lumicon Red filter, 780 minutes (78 x 10 minute subs), 07/29/30/31 & 08/01/02/2012; seeing FWHM 3.0-3.9 per CCDStack

Processing:

CCDStack 2.66.4490.32361, Photoshop CS5.1

Location:

Rolling Roof Observatory, Thousand Oaks, California 91360 (+34d 13m 29s -118h 52m 20s)

Notes: M 39 is another of those objects that 'just' fits my imaging field (~31' x 46') ... hard to tell the cluster stars from the Milky Way field stars.

The CDS identifies the 'dark spots' visible at the southeast corner (lower left) as the top half of LDN 1012.

The CDS identifies the two small Galaxies near the southwestern edge (lower right) of M 39 as LEDA 86597 and LEDA 167495.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 7092
NGC 7092 = M39 = Cr 438
21 31.7 +48 25
V = 4.6;  Size 32

17.5": very bright, very large, about 30' diameter, scattered.  Includes 18 
bright stars mag 7-8.  Most of the brighter stars form a triangular outline 
although a few bright stars are inside and outside.  The bright star at the SE 
corner has about six faint stars close following.  Includes several wide double 
stars.  The bright stars are superimposed on a background of 100-150 faint 
stars.  Fairly uniformly distributed though many stars are in short arcs and 
winding lanes.  The faint stars are no richer than the milky way concentration.  
Best view with 20 Nagler at 100x.

8": very bright, very large, 30' diameter, triangle shape, includes four bright 
stars mag 7 and ten fairly bright stars mag 8-9.  Large and scattered so needs 
very low power.  Partial resolution in 8x50 binoculars.  Naked-eye cluster in a 
dark sky.

- by Steve Gottlieb