Basic object information
Object name: NGC 4609
Object type: Open cluster
Magnitude: 6.9
Size: 6.0'
Number of stars: 40
Magnitude of brightest star: 9.0
Object classification: II 1 p
Description: Cl,pL,pC,cE,st 10
Notes: Near Coalsack

Catalog information
RA (J2000.0): 12h 42m 18.0s
Dec (J2000.0): -63 00' 00"

Constellation: Crux

Observer: Iiro Sairanen
Obs. place: Nangerwalla, Mullewa, Australia
Date/time: 17/18.12.2009 3:05
Telescope: Newton 110/805 mm
Magn: 161x Filter: -
Field: 25' NE Lim.mag: 7.8
SQM: 22.0 (1)21.7 (1) Seeing: 2
Visuality: I Height: 36
Weather: +19C  
A poor group of 10 mag and fainter stars. Why this is in Caldwell catalogue?