NGC 2251 (Lund 232, Cr 101) Open Cluster in Monoceros

Located at: RA 06 hours 34 minutes 39 seconds, Dec +08 degrees 22 minutes 00 seconds

Size: 10' Magnitude: 7.3 Class: III 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:

Red (Hoya 25A) filter, 150 minutes (15 x 10 minute subs), 02/23/2007

Processing:

CCDStack 1.1, Photoshop 7.0

Location:

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

Notes: From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 2251

NGC 2251 = Cr 101 = OCL-499 = Lund 232
06 34 39 +08 22.0
V = 7.3;  Size 10

17.5" (3/12/94): about 40 stars mag 10.5-14 in an 11'x4' fairly rich string NW-
SE.  Includes about 10 brighter mag 11 stars.  The brightest mag 9.5 star is 
part of a small, roundish subgroup on the W side and is a pleasing double with 
components mag 9.5/12 at 10".  This subgroup has three brighter stars and 15 
faint stars mostly W of the double.  The main string is fairly uniform except 
for an empty 3' gap SE of the mag 9.5 star.  Located 5' NW of the cluster is an 
isolated mag 10 star which appears to be a field star.

17.5" (2/1/92): 35 stars mag 10-14 in 12'x6' string NNW-SSE, bright, moderately 
large, fairly rich but not dense.  Consists of 3 main subgroups.  The W group is 
2' diameter and includes a close double star 10/12 at 10".  The NW group is 3' 
diameter and includes two mag 11 stars with three mag 13 stars between.  The SE 
group is largest and includes 15 stars in a 6' string very elongated N-S with a 
close double star.

- by Steve Gottlieb