NGC 6940 (Lund 961, Cr 424) Open Cluster in Vulpecula

Located at: RA 20 hours 34 minutes 36 seconds, Dec +28 degrees 19 minutes 00 seconds

Size: 31' (25') Magnitude: 6.3 Class: III 2 r

North is up

West to the right

Telescope:

8" f5 Newtonian reflector

Camera:

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

Image:

Lumicon Deep Sky filter, 110 minutes (11 x 10 minute subs), 07/21/2007

Processing:

CCDStack 1.2, Photoshop 7.0

Location:

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

Notes:

This open cluster is hardly recognizable in this rich Vulpecula star field and image scale. The listed size of 31 minutes fills this field (top to bottom), as my field is about 31' x 46'.

According to "Star Clusters", by Brent Archinal and Steven Hynes, the size of this open cluster is 25 arc minutes.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 6940

NGC 6940 = Cr 424 = Mel 232 = Lund 961
20 34 26 +28 17.0
V = 6.3;  Size 31

13.1": beautiful rich star field although not dense.  About 100 stars mag 9-14 
resolved including the orange star FG Vulpeculae near the center.  The double 
star 9 Vulpeculae = ?2698 = 8.8/9.7 at 4.5" is off the SW edge.

- by Steve Gottlieb