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RA: 16h 35m 48s
Dec: −45° 38′ 0″
Ch: MSA:1481, U2:407, SA:22
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003)
Type: open cluster, 33p
Mag: B=7.28, V=7.2
Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "middle of a small group of bright stars." On a second occassion he called it "cheif star 9th mag of a small bright clustering group of from 12 to 20 pretty large stars, with stragglers."
Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 4' and the class as 2 3 p.
Vogt. N. & Moffat, AFJ (1973), "Southern Open Star Clusters III." Astron.Astrophys.Suppl., 10, 135-193. [image, table]
"A well-defined cluster sequence is visible" in the two-colour and both colour-magnitude diagrams. ... d = 0.91 kpc and earliest Sp = B1."
The RNGC (Sulentic and Tifft 1973) notes that this is a 7.0 mag open cluster.
"Cat. of Open Cl. south of -45° Decl.", Mem. 17 Mnt Stromlo Obs.
Steve Coe, observing with a 17.5" f/4.5 at 100X, notes: "Bright, small, not compressed, 14 stars in a nice Milky Way field at 135X.
This cluster lies a few degrees south of Mu Normae. Between this cluster and star lies an interesting T-shaped asterism, with the cross-bar of the T extending north south. The cluster's location is marked by a double star, but only uncertain, subjective nebulosity can be seen here with the 11x80's Look for a nice chain of stars due east of the clusterdouble.
The Messier objects
The Bennett objects
The Caldwell list
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