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RA: 06h 05m 0s
Dec: +24° 00′ 0″
Ch: MSA:156, U2:136, SA:5
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003)
Type: open cluster, 21p
Mag: B=8.91, V=8.4
IC 2157. See IC 2156.
Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 5.5' and the class as 2 2 p. He notes: "Mentioned by Barnard (Bd.Atl. pl8). Loose and somewhat irregular group of about 30 stars 12-15th mag."
Photo Index by Jim Lucyk: Sky&Tel. 2/84 p192.
Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "9.5M; 4' diameter; 20-plus faint members; sparse and small; looks distant; nearby to ENE are M-35 and N2158."
Houston writes: "The group, which lacks any central concentration, shines with the total light of a single 8.4 mag star. A 4-inch telescope will easily pick the cluster out of the rich galactic background. Since its brightest stars are 11th mag, the cluster appears best when viewed with magnifications of about 100x." He calls it a "neat cluster. It is a gathering of perhaps two dozen stars packed into a 7' space. It tolerates high power nicely, which helps in this crowded portion of the Milky Way."
Steve Coe, observing with a 13" f/5.6, notes: "Pretty faint, pretty small, not compressed. 19 stars counted at 100X. On a better night, which I rated 8/10, I counted 28 stars, but this cluster is still not much."
6cm - just vis as circ haze.
15cm - rel uninteresting grps not well sep from fld. Srn grp (-57) 3'.5 diam w/just 15 *s m10.5+. Nrn grp is 2'.5 diam w/just eight *s. BS, 4Feb1991, Anderson Mesa.
25cm - fairly faint, not consp. 15 *s in 4'-5' area, m10.5+.
30cm - not obvious @ 149x. three br m11 *s. 238x: 4'.5 diam w/15 *s and some clumpy haze.
Observing site: Little Tycho Observatory
[6h 5m 0s, 24° 0m 0s] A *very* faint smudge, found only with the aid of the finder chart. No stars seen.
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 is randomly scattered which is arranged in an east-west direction.In this open cluster I have counted 14 stars which are magnitude 11.3 and that most of the stars are nearly the same brightness as each other.In overall the stars in this open cluster is not at all separated and that there are some areas of starless patches.This open cluster measures 16.4'x 10.9'with P.A:East/West.Chart No.207,NSOG Vol.1.
The Messier objects
The Bennett objects
The Caldwell list
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