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RA: 17h 25m 29.16s
Dec: −48° 25′ 21.7″
Ch: MSA:1479, U2:408, SA:22
Ref: SIMBAD, Collinder (1931), SEDS
Type: globular cluster
Mag: B=9.95, V=8.87
The NGC calls it only "pretty faint, large." In the 'Notes and Corrections to the New General Catalogue', Stewart notes: "a cluster, not a nebula." It is remarkable that John Herschel did not find this cluster during his methodical sweeps of the southern sky.
James Dunlop discovered this 8th magnitude globular cluster from Paramatta, New South Wales, and included it as No. 417 in his catalogue of 1827. Using a 9-inch f/12 telescope, he described it as "a rather faint nebula, or an irregular round figure, 4' diameter, slightly branched; easily resolvable into stars, with slight compression of the stars to the centre."
It was also reported by Barnard, who observed with a 6-inch refractor at Nashville, Tennessee.
Table IV: A cl., not a neb.
Included in a list of doubtful objects;. A comparativley large cluser of very faint stars, on the edge of the Milky Way.
Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
"Cat. of Open Cl. south of -45° Decl.", Mem. 17 Mnt Stromlo Obs.
The RNGC (Sulentic and Tifft 1973) notes that this is a 9.0 mag globular cluster.
RA 17 25 29.2 (2000) Dec -48 25 22 Integrated V magnitude 7.96 Central surface brightness, V magnitudes per square arcsecond 18.42 Integrated spectral type G4- Central concentration, c = log(r_total/r_core); a 'c' denotes a core-collapsed cluster 1.10 Core radius in arcmin .83. ["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) ]
A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.
Hartung writes "In this fine field sown profusely with stars is one of the less-condensed type of globular cluster, irregularly round, about 2.5' across and resolved into very faint stars, some of which can be seen with a four-inch scattered through the haze and the outlying region. It is surprising that John Herschel's thorough sweeping missed this conspicuous object."
Gerd Bahr-Vollrath (Noosa Heads, Queensland, Australia) observing with an 8-inch f/12 SCT, writes in the The Webb Society Nebulae and Clusters Section Report No. 10, July 1992: "Fairly small round glow. Only a slight increase in brightness towards the core. Appears grainy throughout."
25cm - br, lg, 5' diam. granular @ 150x/190x. viewed on meridian. some brtr fld *s are seen in SW side. vbroad concen, but bright a la M55. BS, 9Jul1980, Anderson Mesa.
"Very faint, it is better seen with averted vision or slightly shaking the telescope. High power required." Gabriel Giust, 1994 April 10, 8-inch f/6.7 reflector, 9.7mm Super Plossl, San Isidro, Buenos Aires.
24/09/93: 11x80 binoculars, strong moonlight: Could not be seen. Could see NGC 6322, 6333, 6266, 6273, etc.
1998-04-23/24, 11x80 tripod-mounted binoculars, Die Boord. Seeing good, transparency below average, dew. F, R, 4.5' glow, light evenly spread out, no fringe. Requires care if it is to be singled out from a diverse field.
16-inch f/10 SCT (127x, 290x)
Pretty round haze no stars resolved in low power. High power reveal a granular surface and a dark lane NE-SW which reminds me of Cen A. Stars spray out more to the SW. Triangle of stars to the SE and a string of 4 stars to the SW around 4' on the sides of the globular.
Location: Pietersburg South 23o 53. East 29o 28.
Sky conditions: Clear.
Date: 4 Julie 1997.
Field of view: 52.7 arc minutes.
ASSA-DSO - Report J
Faint fuzzy small ball. Bright stars group together to the one edge.
Location: Campsite (South 23 16 East 29 26).
Sky conditions: Clear, steadiness good.
Instrument: Meade 8 inch, Super wide-angle, 18mm eyepiece; 36.2' fov
DSO Report N
Large, bright, irregular round globular cluster, not very dense. Faint stars scattered through the haziness. Brighter stars group together outside to the south.
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)
Globular resolved clearly and does not appear to be dense at all. Dark spots and thin dark lanes are visible in the slightly more compact centre. Across the surface stars can be seen. A busy southwestern side with bright star strings spreading towards the outskirts (218x) On account of this busy side the globular appears slightly oval. A star string seemingly looks like a coat hanger is visible 14' arc minutes to the southwest containing about 8 stars of 9th magnitude.
Location:Night Sky Caravan Park,Bonnievale.
Sky Conditions:Whole Milky Way is visible.The sky is clean.
Atmosphere stable with little interference.
In this globular cluster the stars are partially resolved in this cluster and that this cluster has a roundish shape of bright soft light.The stars in this cluster is slightly concentrated towards each other in a halo glowing in the sky among the field stars.Around the outskirts of this globular cluster there are bright chains of stars being clearly seen.The nucleus of this cluster is comparitievely bright and that it is compact.This globular cluster measures 8.2'*8.2'Chart No:29,NSOG Vol.3.
The Messier objects
The Bennett objects
The Caldwell list
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