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RA: 17h 10m 10.42s
Dec: −26° 34′ 54.2″
Ch: MSA:1395, U2:337, SA:22
Ref: SIMBAD, SEDS
Type: globular cluster
Mag: B=9.96, V=9.02
NGC 6293. See NGC 6294.
Synonyms: H VI-012
Discovered in 1785 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "another miniature cluster like the preceding [NGC 6284], but rather coarser."
Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "globular, B, R, psbM, diam 7 seconds, resolved into stars 16th mag." On a second occassion he called it "globular, pB, R, psvmbM, 3.5', resolved into stars 15..16th mag."
The NGC describes it as "very bright, large, round, pretty suddenly brighter in the middle, clearly resolved into stars of 16th magnitude."
Rather irregular globular cluster, nearly R. (visual obs.)
Confirms HOB 15.
Knox Shaw, H. (1915) Note on the nebulae and star clusters shown on the Franklin-Adams plates. M.N.R.A.S., 76(2), 105-107.
Comments on papers by Harding (MNRAS, 74(8)), and Melotte (MemRAS 60(5)) describing objects foundon the Franklin-Adams plates; compares with plates taken with the Reynolds reflector (Helwan Obs Bull. 9-15):
NGC 6293 is a globular cluster and not elongated. [previously included in Class II-Spindle-shaped Nebulae]
"globular cluster, fairly condensed."
Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
Vorontsov-Velyaminov, B. "Integral magnitudes of south star clusters", Astron. Nach. 228, 325. Comparing the brightness of the cluster with the extrafocal images of stars, he estimates the magnitudes as 7.5.
A study by W. W. Morgan of Yerkes Observatory indicates this globular cluster to have a spectral type of F5.
(Sulentic and Tifft 1973) notes that this is a 9.5 mag globular cluster.
Harris, W.E. (1996)
RA 17 10 10.4 (2000) Dec -26 34 54 Integrated V magnitude 8.22 Central surface brightness, V magnitudes per square arcsecond 16.18 Integrated spectral type F3 Central concentration, c = log(r_total/r_core); a 'c' denotes a core-collapsed cluster 2.50c: Core radius in arcmin .05. ["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.
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "8M; 4' diameter; very bright and round with much brighter and denser center; unresolved; looks like EL GAL."
Observer: John Callender
Instrument: 8-inch Dobsonian reflector Location: Carpinteria, CA, USA
Light pollution: light Transparency: fair Seeing: good
Time: Sat Jul 5 07:40:00 1997 UT Obs. no.: 198
Somewhat larger than NGC 6316, fairly condensed, easy with averted vision at 49x.
Houston notes that this globular lies within a short distance of M19. It is "about 2' across and of magnitude 8.4. It can be seen with only a 2-inch aperture and shows nicely in 4 to 8-inch telescopes."
Bennett observed it with a 5-inch short-focus refractor, including it in his list of cometary objects as number 89.
Hartung notes that the cluster lies in a "fine starry field" and is "bright, compressed, well-resolved...about 2' across with irregular edges but no conspicuous outlying stars. An 8-inch telescope is able to resolve it partially but a 6-inch shows only granularity".
Steve Coe, using a 13" f/5.6, notes: " Pretty bright, pretty large, bright in the middle and round. It is resolved at 135X. There is a pretty bright double star at the edge of this globular. NGC 6293 is located just north of B 59, the stem of the Pipe Nebula, therefore there are several dark lanes leading out of the field into the Milky Way."
Binoculars show the cluster in the same field of view and to the east of the bright M 19. A two-inch refractor shows the globular as a faint starlike glow, 8-9th mag. To the west of the cluster lies a line of three 8-9th magnitude stars shown on Uranometria 2000.0. The globular is slightly fainter than these stars.
1998-04-27/28, 11x80 tripod-mounted binoculars, Die Boord. Seeing average, transparency average, dew. "Faint, round, 2.7' cluster. Needs attention to pick out as a bloated star with hazy borders."
A 15.5-inch telescope shows here a medium to small sized, pretty bright globular cluster, irregularly round diffuse glow, with a pretty extended central brighter portion and a fainter smaller halo. The nucleus is extended but there are no stars resolved. There is a faint field star lying to the east-northeast of the cluster. Readily visible at 220x, it could be quite a challenge in smaller telescopes.
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.
Brighter and larger than NGC 6287 (7arc min). Granular appearance, fringy edges with a wide sudden bright core. Not resolved, with a double star a few minutes to the east and faint pinpoint stars in the field rounded this globular off beautiful.
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)
Easily seen, small but out of focus glow. Slightly elongated in an east west direction, no stars resolved. Lovely visual 12th magnitude double star just off the east north east side of the globular. (Mag 8.2; size 7.9'; Brightest stars = 14.3 mag. )
Observing site: Pinnacles overlook
[17h 10m 12s, -26° 35' 0"] A nice cluster, which looks like spilled sugar with averted vision.
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 looks a faint oval halo of light and that this cluster's stars are unresolved.The nucleus of this cluster is slightly compact.The stars in the central core of this cluster grows slightly brighter compared to the stars on the far outskirts of this cluster.Chart No.295 Vol.2.
The Messier objects
The Bennett objects
The Caldwell list
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