NGC 7039 (Lund 981, Cr 431) Open Cluster in Cygnus

Located at: RA 21 hours 11 minutes 12 seconds, Dec +45 degrees 39 minutes 00 seconds

Size: 24' (15');Magnitude: 7.6 Class: IV 2 m

North is up

West to the right

Telescope:

 8" f5 Newtonian reflector

Camera:

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

Image:

Lumicon Red filter, 600 minutes  (60 x 10 minute subs) 07/22/23/27/2010; seeing 2.1-3.2 FWHM per CCDStack

Processing:

CCDStack 2.9.3831.24373, Photoshop 7.0

Location:

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

Notes: According to "Star Clusters", by Brent Archinal and Steven Hynes, the size of this open cluster is 15 arc minutes. Comments from "Star Clusters"; "Archinal: 7' high by 14 wide group of stars. brightest star on NNE side".

Imaged this object, Basel 12 and NGC 7093, while to moon was near full ... all within 6 or 7 degrees of "The Wall" / Mexico section of NGC 7000 (North America Nebula).

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 7039
NGC 7039 = Cr 431 = Lund 981 = OCL-203
21 10.8 +45 37
V = 7.6;  Size 25

17.5": about 125 stars in a 15'-20' diameter.  This is a very large, rich 
triangular group.  Two bright mag 7.5 stars are at the SSW and NNE ends.  Also 
two mag 9 stars are involved.  Very rich in mag 12-13 stars.  Pretty uniform 
cluster with a sprinkling of brighter stars.  Excellent low power milky way 
field using a 20mm Nagler.

- by Steve Gottlieb
Historical Research Notes / Correction for NGC 7039
NGC 7039 is a very large cluster about 20 arcmin long and 7 arcmin wide.  
Though JH says it is "Extended from nf to sp," it is actually extended from
the southwest (sp) to the northeast (nf).  I suspect this is a simple error on
JH's part, though visual observers might want to have a look at the cluster to
be sure.

The position that JH gives is for SAO 50547 on the northeastern edge of the
cluster.  On POSS1, DSS, and GSC, there are two overlapping concentrations of 
stars within the cluster.  The position in the main table is for a point 
midway between the centers of these concentrations. - Dr. Harold G. Corwin, Jr.