NGC 433 (Lund 41, Stock 22) Open Cluster in Cassiopeia

Located at: RA 01 hours 15 minutes 10 seconds, Dec +60 degrees 07 minutes 30 seconds

Size: 2.5' (4.0') Magnitude: -- Class: III 2 p

North is up

West to the right


 14.5" f5 Newtonian reflector


  ST-8XME, self-guided, binned 1x1, temp -20c, camera control MaxIm DL 4.56


Lumicon Red filter, 480 minutes (48 x 10 minute subs), 10/03/04/2017; seeing 2.7-4.6 FWHM per CCDStack

Processing: CCDStack 2.94.6355.18107, Photoshop CS5.1

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

Notes: Beginning of October ... mostly clear weather, fairly poor seeing (with the advent of off-shore winds), and the brightening moon led me to imaging some open clusters (see NGC 189 and Riddle 4) in the north.

According to  "Star Clusters", by Brent Archinal and Steven Hynes, the size of this open cluster is listed as 4.0 arc minutes.

From the NGC / IC Project:

NGC 433 = Stock 22 = OCL-319 = Lund 41

01 15 09 +60 07 36

Size 3'

24" (1/4/14): the most distinctive part of this cluster is a mag 9.3 star surrounded by a 2' cloud (mostly south) of ~15 mag 13-14 stars.  A mag 11 star is at the NW corner, a 50" pair of mag 11 stars is at the SE end and a mag 11.5 star is at the SW corner.  A small string of stars extends from the mag 9.3 star to the southwest.

17.5" (8/16/93): 30 stars mag 10-14 in a 6' triangular outline although very few stars are inside the triangle.  The mag 10 star at the north vertex is surrounded (mostly on the south side) by a rich subgroup of faint stars,   including at least three close multiple systems.  Mag 8.7 SAO 22122 is just south of the triangle and 8' SSW of the mag 10 star in the cluster.

JH discovered NGC 433 = h94 on 29 Sep 1829 and described a "star 8m the chief of a small loose cluster." The mag 9.3 star is on the north side of the cluster. Robert Ball observed the cluster using the 72" at Birr Castle and logged "Loose CL. consisting of 50 or 60 stars of various sizes from about 8 mag down."