NGC 2309 (Lund 272, Cr 122) Open Cluster in Monoceros

Located at: RA 06 hours 56 minutes 04 seconds, Dec -07 degrees 10 minutes 30 seconds

Size: 3.0' (5.0') Magnitude: 10.5 Class: I 2 m

North is up

West to the right

Telescope:

 8" f5 Newtonian reflector

Camera:

  ST-8XME, self-guided, binned 1x1, temp -25c, camera control MaxIm DL 4.56

Image:

Lumicon Red filter, 320 minutes (32 x 10 minute subs), 03/8/10/2009; seeing 2.2-2.7 FWHM per CCDStack

Processing:

CCDStack 1.5.2.1, 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 5.0 arc minutes.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 2309

NGC 2309 = Cr 122 = Mel 56 = OCL-557
06 56 04 -07 10.5
Size 3

17.5": three dozen stars mag 11-15, fairly rich, compact, 4' diameter.  Most 
stars located within two streams.  The brighter stars in the southern stream are 
oriented E-W.  A fainter star lane to N is oriented NW-SE.  At the NW end it 
hooks NE to mag 9 SAO 133914 about 4' N of the cluster's center.  Includes 
several close pairs with two pairs near the center and a double star 11/14 at 7" 
separation at the W end.

- by Steve Gottlieb