Open Cluster NGC 752

NGC 752
NGC 752: Asterism «Golf Putter» with cluster NGC 752 as ball. Section of the DSS2 [147]


This open cluster was probably first seen by Italian astronomer Giovanni Batista Hodierna before 1654. He observed in Palermo, Sicily using a small galilean refractor with 20x magnification. His mentions of a nebula «juxta Triangulum» mentioned on pages. 7, 11 and 48 could also refer to Messier 33. His classification of nebula was: nebulous for the naked eye, but resolved in a telescope. Unfortunately his publication was little known outside Sicily. It had been rediscovered in the 1980s. [128, 196, 217, 277, 364]

William Herschel first observed this cluster on 24 August 1783 with his 6.2-inch reflector. His sister Caroline independently discovered the cluster on 29 September 1783 with her 4.2 inch comet-seeker reflector. [364] Later on 21 September 1786 while doing his sweeps using his 18.7 inch telescope William Herschel listed the cluster as VII 32 (class VII = pretty much compressed clusters of large or small stars). He noted: «A very large coarsely scattered cluster of very large stars, irregularly round, very rich, takes up 1/2 degree like a nebulous star to the naked eye.» [464] Dreyer added this cluster as NGC 752 to his «New General Catalogue» in 1888. [313]

Physical Properties

NGC 752 is an old and loose open cluster. The age is estimated to 1.12 billion (109) years. [138]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
DesignationNGC 752
TypeOCL (III1m)
Right Ascension (J2000.0)01h 57m 35.0s
Declination (J2000.0)+37° 50' 00"
Diameter75 arcmin
Visual magnitude5.7 mag
Metric Distance0.458 kpc
Dreyer DescriptionCl, vvL, Ri, st L & sc
Identification, RemarksOCL 363

Background Galaxies

A number of small and faint background galaxies can be seen through the open cluster NGC 752. These may pose a nice challange for CCD imagers and large dobsonian users. The largest and brightest of these is IC 179, discovered on 28 June 1890 by Lewis Swift using the 16 inch refractor at Warner Observatory. [364] The other galaxies are mostly from the «Uppsala General Catalogue of Galaxies» (UGC), compiled by Peter Nilson in 1973. [459]

«Catalogue of Principal Galaxies» Paturel et al., 1989 [144]
PGC 712401 54 57.7+37 20 33S.9 x .615.4165UGC 1380, CGCG 522-59, KUG 151+370
PGC 722001 55 58.6+37 07 49S1.2 x 1.114.75218UGC 1398, MCG 6-5-54, CGCG 522-69, IRAS 1530+3653
PGC 726301 56 23.8+37 12 58SB1.1 x .615.34458100UGC 1404, MCG 6-5-56, CGCG 522-73
PGC 730001 56 46.1+36 53 14S1.2 x .614.865UGC 1416, MCG 6-5-59, CGCG 522-81
PGC 748901 58 55.9+37 44 45 x 15.6CGCG 522-95
PGC 757902 00 11.3+37 36 14SB1.3 x 1.114.7404415UGC 1474, MCG 6-5-76, CGCG 522-100
PGC 758102 00 11.5+38 01 15E1.8 x 1.513.44188110IC 179, UGC 1475, MCG 6-5-75, CGCG 522-101
PGC 764602 00 55.0+38 12 42SB1.8 x .713.9410787UGC 1493, MCG 6-5-77, CGCG 522-102, IRAS 1579+3758

Finder Chart

The open cluster NGC 752 can be found in the constellation Andromeda, lying about halfway between the stars Almach (γ Andromedae) and β Trianguli. On a dark site it is visible to the naked eye. With binoculars or a small telescope (ca. 4° field of view) the asterism «Golf Putter» with the cluster NGC 752 as the ball can be identified. The two bright stars with 56 And are the club head. [129] If you own a large aperture telescope, increase magnification and use the 2° closeup of the finder chart for hunting down the tiny background galaxies. The best time for observation is in the months June through March.

Finder Chart Open Cluster NGC 752
Open Cluster NGC 752 in constellation Andromeda. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

More Objects Nearby (±15°)