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RA: 17h 05m 9.34s
Dec: −22° 42′ 28.8″
Ch: MSA:1395, U2:337, SA:22
Ref: SIMBAD, SEDS
Type: globular cluster
Mag: B=11.49, V=10.3
Synonyms: H II-195
Discovered in May 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "pB, cL, iR, lbM, r."
Observed by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "globular, irregular round, gpm comp M, 3' diam, barely reslved into stars 16..18th mag."
The NGC description reads: "considerably bright, large, round, first gradually then pretty much compressed to the middle, clearly resolved into stars of 16th magnitude".
Hinks, A. R. (1911) On the galactic distribution of gaseous nebulae and of star clusters. MNRAS, 71(8), 693-701.
List 6: "NGC numbers of clusters classed as globular, not in Bailey's catalogue"
Bailey, S.I. A catalogue of bright clusters and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.
The RNGC (Sulentic and Tifft 1973) notes that this is a 11.0 mag globular cluster.
RA 17 05 09.4 (2000) Dec -22 42 29 Integrated V magnitude 9.35 Central surface brightness, V magnitudes per square arcsecond 18.33 Integrated spectral type F5- Central concentration, c = log(r_total/r_core); a 'c' denotes a core-collapsed cluster 1.60 Core radius in arcmin .26. ["Catalog Of Parameters For Milky Way Globular Clusters", compiled by William E. Harris, McMaster University. (Revised: May 15, 1997; from http://www.physics.mcmaster.ca/Globular.html; Harris, W.E. 1996, AJ, 112, 1487) ]
Uncloaking Globular Clusters in the Inner Galaxy. [2012AJ....143...70A]
The significant extinction is a consequence of the cluster's projected position, close to the Ophiuchus dust complex.
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "10.5M; 3' diameter; like nearby N6284 but larger, fainter, unresolved, and less compressed."
Hartung notes that "The Milky Way field in which this globular cluster lies is partly veiled by absorbing matter...which blots out most of the background stars. The cluster is about 1.5' across, irregularly round, not bright gand just resolved into very faint stars with a 12-inch. All that a 4-inch telescope shows is a faint round spot in an almost empty field."
Steve Coe, using a 13" f/5.6, notes: " Pretty bright, pretty large, somewhat elongated 1.5 X 1, ten stars resolved at 220X."
In a 15.5-inch telescope at 220x, this cluster appears regular in shape, round, diffuse, no distinction between the concentrated nucleus and the outlier. Unlike the many globular clusters in this area, which all lie in pretty rich starfields, NGC 6287 lies near the edge of the dark nebula Barnard 51, and the stars readily visible within half a degree number under half a dozen.
Location: Campsite (South 23 16 East 29 26).
Sky conditions: Very clear semi transparent.
Instrument: Meade 8" (Super plossl 26mm and wide-angle 18mm eyepiece).
Date: 26 to 28 April 1998.
Field of view: 36.2arc minutes.
Very faint, round small glow of light. Even brightness spills over the whole of this globular cluster. Not resolved and embedded in a bare starfield with no sharp edges.
12-inch f/10 SCT (EP: 2-inch 32mm SW 95x 42' fov; 2-inch 14mm UW 218x 23' fov)
Very faint, round and small glow of light. Even brightness spills over the whole of this globular cluster. Not resolved, uneven with no sharp edges, embedded in a very bare star-field on the edge of the dark Barnard 51 nebula. Just a few field stars can be seen to the southwest. Discovered by William Herschel in May 1785. (Mag 9.3; size 5.0'; brightest stars = 14.5 mag. )
Observing site: Pinnacles overlook
[17h 5m 12s, -22° 42' 0"] A faint, loose, small GC, I managed to resolve about 20 stars.
Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.
This globular cluster has the resemblance of a very small snowball at 75*and is seen as a mottled halo of 12th magnitude stars.There is no resolution in this cluster at all and that the stars are neatly arranged in a tight periphery towards the central core of this globular cluster.In overall the nucleus of this cluster is strongly condensed.From the central nucleus of this globular cluster the stars are comparitely brighter than the stars on the far outskirts of this cluster.Chart No.295,NSOG Vol.2
The Messier objects
The Bennett objects
The Caldwell list
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