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RA: 04h 48m 29s
Dec: +10° 55′ 48″
Ch: MSA:208, U2:179, SA:11
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003), Skiff20080430-T
Type: open cluster, 23m
Mag: B=7, V=6.4
Discovered in 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "a cluster of large scattered stars, 10' or 12' in extent, with a vacany in the middle."
(Lick Obs. Bulletin, Vol 14, No 420) gives the diameter as 14' and the class as 2 2 p.
(Sulentic and Tifft 1973) notes that this is a 8.0 mag open cluster.
See: Houston, W.S. (1975) Four neglected deep-sky wonders. Sky&Telescope, Dec, 420.
Coe, using a 13" f/5.6, notes: "Pretty bright, pretty large, not rich, not compressed, cluster of 19 stars with several nice pairs at 100X. A few stars of 8 to 9 mag show in the 11X80."
Alldays (22.50S, 20.12E, 770m).
12-inch f/10 SCT (95x, 218x)
Subtle elongated string in a NW to SE direction. The south end of the formation is rounded off with a knot of stars. Towards the middle the string shape in a half moon that is open to the western side. The cluster appears to be more busy with outliers to the SE and well outside the field of view. The cluster contain about 20 stars which sever appear to be in pairs. Displays an uneven long string in a NW-SE direction. In the west swing of this string 8' a lovely trapezium of four stars can be seen, the one to the NE is yellow. Must sketch this one. I estimate the whole cluster about 13'.
Observing site: Little Tycho Observatory
[4h 48m 30s, 10° 56m 0s] A loose open cluster, swept up when looking for a double (Struve 535!) with a poorly aligned telescope. Obviously a cluster, but unspectacular.
The Messier objects
The Bennett objects
The Caldwell list
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