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RA: 16h 49m 23.5s
Dec: −44° 43′ 53″
Ch: MSA:1460, U2:407, SA:22
Ref: NGC/IC, Archinal&Hynes (2003)
Type: open cluster, 12m
Mag: B=?, V=10.1
NGC 6216 = NGC 6222. JH recorded the cluster on four different sweeps. On three of those (NGC 6216), his RA is accurate. However, the fourth sweep (NGC 6222) has the RA 1 min 20 sec following; the Dec is the same. The description for N6222 fits N6216, and there is only a Milky Way star field at N6222's position. The identification, adopted in RNGC and ESO, is pretty sure.
The NGC also suggests that 6222 could be Dunlop 456, but it is now believed that this Dunlop object corresponds to NGC 6259. NGC 6216 is described as "pretty small, pretty rich, pretty compressed, stars of magnitudes 12..15."
James Dunlop discovered this open cluster from Paramatta, New South Wales, and included it as No. in his catalogue of 1827. Using a 9-inch f/12 telescope, he described it as "a faint nebula, about 4' or 5' diameter, irregular round figure, easily resolvable into stars; with stars of larger magnitudes scattered in the preceding side of it."
Observed by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "a pretty rich cluster of small stars, 11th mag and under, broken up into two or three groups; fills two-thirds of field." His second observation was recorded as "a round cluster of 13th mag stars, gradually brighter in the middle; 4'; with two appendages of stars, north and south, making together a long cluster." His third and final observation records it as "pretty rich, round, pretty compressed in the middle, very little brighter in the middle, 4' diameter, stars discrete 12..15th mag and fainter." This set of observations was recorded as No. 3648 (NGC 6216) in his Cape of Good Hope observations, and the three observations were made on 1 June, 1 July and 27 July, 1834. On the night of 3 June 1834, he recorded No. 3650 as a "very large, very rich cluster, not brilliant, not materially compressed in the middle, full 20' diameter, stars 12..13th mag." This object received the NGC number 6222, and is now believed to be a re-observation of NGC 6216.
Bailey, examining a Bruce plate (Harvard Annals, Vol 72, No 2), describes it as "rich region of the Milky Way."
Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 3.8' and the class as 2 2 m. He notes: "Melotte 152 should be identified with [NGC 6216] and not with NGC 6222."
The RNGC (Sulentic and Tifft 1973) notes that this is a nonexistent object. Their coded description reads =6222 COLLINDER.
Observing with a 15.5-inch telescope, it appears as a very small, faint open cluster, consisting of about six slightly brighter stars surrounded by a clump of much, much fainter stars. The cluster seems vaguely triangular in shape, with the triangle's base defined by about 5 of these brighter stars. The surrounding starfield is pretty rich.
Location: Campsite Farm. (South 23 16 East 29 26)
Sky conditions: clear.
Instrument: Meade 8 inch (Super wide-angle 18mm eyepiece.
Date: 14 May 1979.
ASSA-DSO - Report H
Small, loose and faint open cluster with not a lot of stars involved. Cluster irregular and extended a bid. Close to NGC 6192 in a busy starfield.
Small, loose and faint, open cluster with not a lot of stars involved. Cluster irregular and slightly extended. Busy starfield.
12-inch f/10 SCT (EP: 2-inch 40mm SW 76x 53' fov; 2-inch 32mm SW 95x 42' fov; 2-inch 14mm UW 218x 23' fov)
A faint tight grouping, which is barely visible against the background star-field. With greater magnification (218x) one can see approximately two-dozen faint stars with a slightly dense centre. Dainty and somewhat elongated in a south north direction. With a magnification of (218x) two visual doubles can be seen in the centre from which the stars ripple outwards in a roundish shape. (Mag 10.0; size 4.0'; number of stars = 40. )
Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.
This open cluster,consisting of 12th magnitude stars are strongly concentrated towards each other,is well detached from the background,and looks like a hazy patch.Chart No.340,NSOG Vol.2.
The Messier objects
The Bennett objects
The Caldwell list
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