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RA: 18h 13m 38.88s
Dec: −31° 49′ 35.2″
Ch: MSA:1414, U2:377, SA:22
Ref: SIMBAD, SEDS
Type: globular cluster
Mag: B=10.78, V=9.47
Synonyms: H II-201
Discovered in 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "F, pL, lbM, r."
Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "globular, pB, L, R, glbM, 4' diam, resolved into stars 15m." On a second occassion he called it "globular, vB, L, R, gbM, 3' diam, resolved. In milky way." His third observation was recorded as "globular, pB, R, vglbM, 3.5' diam, resolved." On July 16, 1836 he noted: "Found in equatorial [5-inch refractor] in a zone review for double stars, where it appeared as a F R neb 1' diam."
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.
Globular cluster 1.5' diameter. Near edge of plate.
2'x2', globular cluster, rather sparse in centre.
p 22: There are a few individual globular clusters, NGC 4372, NGC 6144 and NGC 6569 that are in or near recognized dark or luminous nebulae. … NGC 6569 is in a rich star field in Sagittarius but may also be involved in wisps of obscuring nebulosity."
The RNGC (Sulentic and Tifft 1973) notes that this is a 10.5 mag globular cluster.
A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.
RA 18 13 38.9 (2000) Dec -31 49 35 Integrated V magnitude 8.55 Central surface brightness, V magnitudes per square arcsecond 18.08 Integrated spectral type G1: Central concentration, c = log(r_total/r_core); a 'c' denotes a core-collapsed cluster 1.27 Core radius in arcmin .37. ["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) ]
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "10M; 2' diameter; unresolved, bright, round glow with little center brightness; double star B-1353 nearby; 6.5M star 10' due S is hopeless DBL ST B-1353 (0.1" separation; both 7M)."
Steve Coe, observing with a 13" f/5.6, notes: "Bright, large, round, resolved 12 stars with a very grainy backround at 165X."
30/04/93: Observing with a 6-inch f/8.6 Newtonian, this cluster appears as a faint, nebulous extended haze, not small, can be seen at 52x. There is a 7th mag star South.
12-inch Meade, 40mm eyepiece, 53' fov. 1997-08-05, fair sky conditions "A hazy small faint globular cluster difficult to determine. Uneven disk situated in a beautiful medium starfield." [Magda Streicher, Pietersburg 23-53S, 29-28E]
12-inch f/10 SCT (EP: 2-inch 40mm SW 76x 53' fov; 2-inch 14mm UW 218x 23' fov; 2-inch 8.8mm UW 346x 15' fov)
A hazy, small, globular cluster difficult to determine. Slightly getting brighter to a wide core, but could not resolve its stars. The edges however show again a slightly sandy and ruff texture. Lovely white 7th magnitude star 8' arc minutes straight south in the field of view (76x). William Herschel discovered this globular in 1784 with an 18 speculum.
Observing site: Pinnacles overlook
[18h 13m 36s, -31° 50' 0"] A compact cluster whose stars made resolution difficult.
Location:Night Sky Caravan Park,Bonnievale.
Sky Conditions:Whole Milky Way is visible.The sky is clean.
Atmosphere stable with little interference.
This globular cluster looks like a soft snowball that is vaguely out of focus and that the stars in this cluster is unresolved and no resolution is seen in this globular cluster.The nucleus of this cluster is very condensed in the center.This globular cluster measures 4.3'*4.3'.Chart:No.322,NSOG Vol.2.
The Messier objects
The Bennett objects
The Caldwell list
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