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RA: 01h 57m 35s
Dec: +37° 50′ 0″
Ch: MSA:123, U2:92, SA:4
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003), Skiff20080430-s
Type: open cluster, 22r
Mag: B=6.47, V=5.7
Synonyms: H VII-032
Discovered in 1786 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "a vL coarse scattered cluster of vL stars, irregularly round, very rich, takes up half a degree, like a nebulous star to the naked eye."
Described in the NGC as "a very very large cluster of stars, rich, stars large and scattered."
In the 5th edition of Webb's Celestial Objects for Common Telescopes it is described as "wide, rich region, especially of small stars."
Notes that "the group is actually more conspicious in good binoculars than in a telescope." The apparently brightest star in the cluster, of magnitude 7.1, has been shown not to be a member of the cluster.
A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.
Vorontsov-Velyaminov, B. (1925) "Catalogue of integrated magnitudes of star clusters", Astron. Nach. 226.195. Comparing the brightness of the cluster with the extrafocal images of stars, he estimates the magnitude as 7.03.
Raab, S. (1922) A research on open clusters. Lund Medd. Astron. Obs. Ser. II, 28, 1.
Based of F-A plates: "L Cl, very thin even at the centre; No perceptible condensation. Fiarly regular form. At the centre are found many * which lies by twos very close together. Not well sep. from surroundings."
Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
Journal BAA, 35, p159
A loose open cluster, about 1 degree in diameter, not very well separated from its surroundings. ... Sirius would be at its confines if the Sun were at its centre.
Trumpler (Lick Obs Bulletin, Vol 14, No. 420) gives the diameter as 45' and the class as 3 1 m.
"A Catalogue of Estimated Parallaxes of 112 Nebulae, Open clusters and Star Groups", Vol 36 (4), p 107-115.
"Very open thin cluster." He gives the approx. diameter as 51 arcmin.
The RNGC (Sulentic and Tifft 1973) notes that this is a 6.5 mag open cluster.
Photo Index by Jim Lucyk: Observer's Guide (Astro Cards) 9-10/88 p32, Astronomy mag. 11/86 p58, Burnhams V1 p152.
Hartung calls this an "interesting cluster of scattered stars, 8-9th mag and fainter, with no central condensation; it is about 45' across and needs a karge field with low magnification. In it are two strongly curved lines of stars preceding."
described as "a very large cluster with elongation. Stars are scattered outwards, fans out in all directions. Bright stars of similar magnitude noted, counted around 70 stars. 8-inch, 48x."
Houston calls it "one of the least known [open clusters] .. a big splashy open cluster in eastern Andromeda. ... it has about 70 stars scattered over an area three-quarters of a degree across, making it a fine object for binoculars. Since most of the cluster's stars are within the reach of a 6-inch telescope, the view is not enhanced much with a larger aperture. The bright 7th mag star near the cluster's eastern edge is not physically associated with the group. K. Glyn Jones of the Webb Society notes thatthe clustrer appears to fill the 65' field of his 8-inch telescope at 40x, and that many of the stars are in pairs." It has an integrated magnitude of 5.7 according to Skiff, and is larger than half a degree across.
Harrington calls it "one of the largest and brightest non-Messier open clusters north of the equator. With its five dozen stars scattered across nearly a full degree of sky, this stellar troupe is made for giant binoculars and rich-field telescopes. Even 7-power glasses will show a few of the brightest suns, while 11-power binoculars reveal a multitude of fainter ones. Perhaps my finest view of NGC 752 was through a 4.5-inch rich-field reflector. Dozens of stellar denizens glistened across the field. Many formed attractive pairings, while others appeared in long, intertwined threads." In his book "Touring the Universe through Binoculars" he calls it a "large loosely structured open cluster . . measuring about 50' of arc across, NGC 752 holds about 75 stars within its grasp, not all of which are resolvable through binoculars."
Rick Raasch writes in "The Focal Point", Volume 6, No. 2 (1993) "NGC 752 A large and splashy open cluster which is best seen in the viewfinder or binoculars. It is about 1/4 degree in size, with over 150 relatively bright stars arranged in many curving chains. Well detached from the background stars and very pretty."
Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "6M; 45' extent! irregular and sparse; 70-plus members spread over a very large area."
naked eye - vis w/o difficulty from a dk site. unres.
6cm - sighted from lambda Arietis.
- nice, pretty rich, but unconcen cl. many pairs and colored *s. 80 *s in
45' area, irreg outline. m6 pair SW is a pretty red and yellow. CBL.
- pretty rich w/little concen. 60 *s in 50' fld. pretty colored pair on SSW.
sev pairs. br * w/two colored comps on E side of cl. CBL.
7cm - lg br cl @ 30x w/br wide pair 56 And on S. 50' diam w/80-90 *s vis @ 30x.
broad concen. BS, 26Nov1992, Anderson Mesa.
15cm - a lg widespread cl w/75 *s vis, m8-12. shaped in an irreg circ a degree
across. BS, 5Sep1970, FtL.
- big & br @ 30x/1.6 deg fld w/56 And on SW periphery. 50x: 250 *s to m~13
(one quadrant counted). mod broad concen of *s across center, *s
appearing in wide pairs, triangles, and little grps. typical pair on W
periphery: 10,10; 20"; 220. 1.2 deg diam overall, but lots of fld *s SW
make for apparent extn in that direction. BS, 19Nov1989, Anderson Mesa.
25cm - fills lox fld. irreg round w/long strings. 75 *s. BS.
Alldays (22.50S, 20.12E, 770m).
12-inch f/10 SCT (95x)
Very loose cluster splash with various magnitude stars, somewhat elongated NE-SW. The middle been dominate with a tri-angle of brighter stars, and a sling of faint stars swing out towards the south. Large and bright, stars going out in the field of view. About 50 stars, a red double.
The Messier objects
The Bennett objects
The Caldwell list
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