Open Cluster NGC 752

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

History

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, © 2022 Dr. Wolfgang Steinicke [277]
Designation NGC 752
Type OCL (III1m)
Right Ascension (J2000.0) 01h 57m 35.0s
Declination (J2000.0) +37° 50' 00"
Diameter 75 arcmin
Visual magnitude 5.7 mag
Metric Distance 0.458 kpc
Dreyer Description Cl, vvL, Ri, st L & sc
Identification, Remarks WH VII 32; h 174; GC 457; OCL 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 RA Dec Type Dim Btot HRV PA Names
PGC 7124 01 54 57.7 +37 20 33 S .9 x .6 15.4 165 UGC 1380, CGCG 522-59, KUG 151+370
PGC 7220 01 55 58.6 +37 07 49 S 1.2 x 1.1 14.7 5218 UGC 1398, MCG 6-5-54, CGCG 522-69, IRAS 1530+3653
PGC 7263 01 56 23.8 +37 12 58 SB 1.1 x .6 15.3 4458 100 UGC 1404, MCG 6-5-56, CGCG 522-73
PGC 7300 01 56 46.1 +36 53 14 S 1.2 x .6 14.8 65 UGC 1416, MCG 6-5-59, CGCG 522-81
PGC 7489 01 58 55.9 +37 44 45 15.6 CGCG 522-95
PGC 7579 02 00 11.3 +37 36 14 SB 1.3 x 1.1 14.7 4044 15 UGC 1474, MCG 6-5-76, CGCG 522-100
PGC 7581 02 00 11.5 +38 01 15 E 1.8 x 1.5 13.4 4188 110 IC 179, UGC 1475, MCG 6-5-75, CGCG 522-101
PGC 7646 02 00 55.0 +38 12 42 SB 1.8 x .7 13.9 4107 87 UGC 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 to February.

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]

Objects Within a Radius of 10°

References