Telescope:

 8" f5 Newtonian reflector

Camera:

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

Image:

Lumicon Red filter, 290 minutes (29 x 10 minute subs), 02/14/25/2009; seeing 2.1-2.9 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:

This image replaces a red filtered 60 minute Track & Accumulate image from 02/24/2006.

According to "Star Clusters", by Brent Archinal and Steven Hynes, the size of this open cluster is 12 arc minutes.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 2506

NGC 2506 = Cr 170 = Mel 80 = OCL-593
08 00 02 -10 46.2
V = 7.6;  Size 7

17.5" (3/12/94): 75 stars in 10' diameter at 220x.  The brightest members are a 
wide pair of mag 11/12 stars at the west end with a separation of 27" oriented 
SW-NE and a mag 11.5 star at the east end.  Rich in mag 13-14 stars with a 
roughly circular outline except for a "bite" on the south side.  The richest 
subgroup is following the two brighter stars at the west end and is 3' diameter 
forming a "C" shaped asterism opening to the south over haze and is quite 
striking.

13" (2/23/85): at 220x, ~35 stars visible, many in a winding row.  A number of 
brighter mag 11 stars surround the group.

- by Steve Gottlieb