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RA: 07h 24m 40s
Dec: −20° 56′ 42″
Con: Canis Major
Ch: MSA:320, U2:319, SA:19
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003)
Type: open cluster, 23m
Mag: B=8.88, V=8.4
Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "cluster, irregularly round, pm compressed, 6'. Stars of mixed magnitudes." The second record reads: "cluster, 7th class, pretty compressed, 4' or 5' in extent. Stars 12th mag. ."
Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 6' and the class as 1 2 p.
Burnham calls this a pretty small, pretty much compressed open cluster, 2' across with about 50 stars of 12th mag and fainter.
Vogt. N. & Moffat, AFJ (1972), "Southern Open Star Clusters I." Astron.Astrophys.Suppl., 7, 133-167. [image, table]
"This cluster contains few bright stars and many faint ones". They determine the distance as 1.97kpc and note that it lies in the local arm of the Galaxy.
Photo Index by Jim Lucyk: Astronomy mag. 2/88 p90.
The RNGC (Sulentic and Tifft 1973) notes that this is a 8.5 mag open cluster.
Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "8.5M; 4' diameter; 50-plus 12M and dimmer members; very small and compressed group; small OPN CL just to SE is N2384 (7.4M; 2' diameter) 12-plus 9M and dimmer members in this small sprinkle."
Steve Coe, using a 17.5" f/4.5, notes: "not much at any power, faint brightening, small nebulous spot at 100X."
Vogt & Moffat I: three brtr *s V=9.9, 9.8, 9.8.
15cm - mod f cl just res @ 80x. 140x: 2'.5 diam and well concen w/two doz *s of
m12+ and three brtr *s strung across cl. sep of wider two of these = diam
of cl. BS, 27Feb1990, LCO.
25cm - 3'-4' diam w/25 *s. NE are two, W is one fairly br * inv w/cl. cl *s are
- pretty consp. 5' diam w/at least 20 *s somewhat concen, mostly m11+.
three m10 *s straddled across it. nice. BS, 25Jan1982, Anderson Mesa.
Observing site: Little Tycho Observatory
[7h 24m 48s, -20° 56' 0"] Only 3 of the brightest stars in this cluster are visible, it needs a darker sky. It is in a rich field, though. WikiSky: A group of around 20 stars, 11mv... form a cloud around the bright trio that was seen through the light pollution.
Location:Blesfontein Guest Farm,Sutherland.
Sky Conditions:The most crystal clear sky possible.Dark moon and stars magnitude 6 and fainter are visible with the naked eye.Excellent clean sky,limited star flickering and brilliant objects.
This open cluster looks like a misty glow which consists of 11-13th magnitude stars.At 75x this open cluster is well positioned in a north south direction.This open cluster is well detached and that most of the stars are nearly the same brightness as each other.This cluster is strongly concentrated.This open cluster measures 4'x 3'with P.A:North/South.Chart No.96,NSOG Vol.1.
The Messier objects
The Bennett objects
The Caldwell list
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