NGC 869 (Lund 73, Cr 24) Open Cluster* in Perseus

Located at: RA 02 hours 19 minutes 04 seconds, Dec +57 degrees 08 minutes 06 seconds

Size: 29' (18') Magnitude: 5.3 Class: I 3 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 Red filter, 610 minutes (61 x 10 minute subs), 10/31 & 11/1/2/2011; seeing 2.8-5.8 FWHM per CCDStack

Processing:

CCDStack 2.50.4324.19668, Photoshop CS 5.1

Location:

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

Notes:* This is the western half of the the "Double Cluster". This image of the "Double Cluster" is centered between the two clusters.

According to "Star Clusters", by Brent Archinal and Steven Hynes, the size of this open cluster is 18 arc minutes.

From the NGC / IC Project:

Contemporary Visual Observation(s)
NGC 0869 = h Per = Cr 24 = Double Cluster
02 19 04 +57 08.1
V = 3.5;  Size 30

17.5": this is the brighter and richer western member of the famous "double 
cluster". Includes a mag 6.6 star near the center and a mag 6.7 star 2.5' NNE.  
Close following the mag 6.6 star is a neat parabolic group of five stars opening 
towards the star.  On the W side of this star is a rich group of ~20 stars 
mostly arranged in an incomplete ring.  A faint curving string of stars from the 
mag 6.7 star leads to the parabolic quintet.  The 20' field at 220x has too many 
stars to count, but probably has ~200 stars.

8": this is the western component of the "double cluster".  Very bright, large, 
about 30' diameter.  Very rich with about 100 stars resolved, includes several 
bright mag 6.5-7.0 stars in the center.  Forms a pair with N884 at edge of 100x 
field.

- by Steve Gottlieb