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RA: 21h 01m 29.43s
Dec: +16° 11′ 14.4″
Ch: MSA:1215, U2:209, SA:16
Ref: SIMBAD, SEDS
Type: globular cluster
Mag: B=?, V=11.4
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Synonyms: H I-052
Discovered in 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "vB S R gmbM resolvable."
This globular cluster is described in the NGC as bright, pretty large and round, growing gradually brighter towards the middle.
A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.
p.178: "Six clusters noted in Lick Obs. Bull., No.219 (Descriptions of 132 Nebulae and Clusters photographed with the Crossley Reflector) are not included in the catalogue.
NGC 7006: Resembles NGC 4147 [NGC 4147: Appears as a nebulous star with trace of faint surrounding nebula. Diameter 1'. Appearance not inconsistent with description in L.O.B. but impossible to tell on this scale photograph whether it is a globular cluster or not.]
(Sulentic and Tifft 1973) notes that this is a 11.5 mag globular cluster.
RA 21 01 29.5 (2000) Dec +16 11 15 Integrated V magnitude 10.56 Central surface brightness, V magnitudes per square arcsecond 18.50 Integrated spectral type F6- Central concentration, c = log(r_total/r_core); a 'c' denotes a core-collapsed cluster 1.42 Core radius in arcmin .24. ["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) ]
Photo Index by Jim Lucyk: Burnhams V2 p832, Astronomy mag. 9/87 p102.
Sanford notes that "it is thought to be one of the most remote globular clusters, lying in intergalactic space at a distance of 150,000 light years. It appears as a small glow, brighter in the centre. At this distance the individual stars are much too faint to resolve in amateur-sized telescopes."
Houston notes that this cluster is a relatively easy object for a 6-inch. It appears about 1' across and magnitude 11.5. He adds: "Large telescopes may show it with a clumpy appearance, but I doubt it can be resolved in any amateur instrument." Houston called it a challenging globular, and wrote in 1976 : "its total visual magnitude is about 10.5, but its angular diameter of only 1' makes it necessary to search carefully. More than 50 power should be used, and with my 4-inch 100 seems best. Recently I tried to find it with 16x40 binoculars mounted on a tripod. Though I knew exactly where to look, I could not distinguish the cluster."
Hartung notes: "It is a moderately bright symmetrical haze about 1' across, rising greatly to the centre . . quite irresolvable with 30cm. It may be seen with 10.5cm but needs care in finding."
Steve Coe, in "SACNEWS On-line for August 1996", using a 13-inch reflector, notes: NGC 7006 is pretty bright, pretty small, round, very bright middle and very compressed at 100X. This very distant globular is one of the most mottled objects I have ever seen in the 13" at 180X. This extremely grainy globular has only shown me stars on its' face one time. Using my old 18" f/6 at 210X, I saw 3 stars superimposed on the surface of NGC 7006. One was held steady, the other two appeared and disappeared with the seeing. This was on a night I rated 8/10 for transparency and 7/10 for seeing. While viewing this deep space wanderer, think of the view of Our Galaxy you would be seeing from a planet in this cluster at 180,000 light years away. It is located at 21 01.5 +16 11.
Steve Coe, observing with a 13" f/5.6, notes: "Pretty bright, pretty small, round, very bright middle and very compressed at 100X. This very distant globular is one of the most mottled objects I have ever seen in the 13" at 180X. This extremely grainy globular has only shown me stars on its' face one time. Using my old 18" f/6 at 210X, I saw 3 stars superimposed on the surface of NGC 7006. One was held steady, the other two appeared and disappeared with the seeing. This was on a night I rated 8/10 for transparency and 7/10 for seeing. While viewing this deep space wanderer, think of the view of Our Galaxy you would have from 180,000 light years away."
John Bortle (Webb Society Quarterly Journal, January 1976) using 10x50 binoculars, estimates the visual magnitude as 10.4.
Listed by the Herschel Club, described as "small, faint, difficult to see. Use averted vision to spot this round ball of fuzz that becomes brighter towards the centre. 8-inch, 48x."
Rick Raasch writes in "The Focal Point", Volume 6, No. 1 (1993) "This small, unresolved globular cluster is unremarkable until you realize that it is some 185,000 light-years distant, comparable to the distance of the Magellanic Clouds, and may actually not even belong to the Milky Way's system of globulars."
Observer: Scott Hogsten
Your skills: Intermediate (some years)
Date/time of observation: Aug, 27, 1998 23:00 EDT
Location of site: Perkins Obs. Delaware Ohio (Lat , Elev )
Site classification: Suburban
Sky darkness: 4.7 Limiting magnitude
Seeing: 6 1-10 Seeing Scale (10 best)
Moon presence: Minor - crescent or far from object
Instrument: 12.5: f5 Dob
Magnification: 150x, 220x
Category: Globular cluster.
Data: mag 10.6 size 2.6'
Position: RA 21:01 DEC 16:11
This is a small round globular cluster. I found it fairly bright (and brighter towards the middle as well) but I could not resolve any component stars of the globular itself.
Your skills: Intermediate (some years) Date/time of observation: 10/16/1999 21.20 UT Location of site: Alphen ad Rijn, Netherlands (Lat 52.09N, Elev ) Site classification: Suburban Sky darkness: 5.0 Limiting magnitude Seeing: I-II I-V Seeing Scale (I best) Moon presence: None - moon not in sky Instrument: 8" F/6 Dobsonian Magnification: 49X, 98X, 203X, 244X Filter(s): none Object(s): NGC 7006 Category: Globular cluster. Class: Constellation: Del Data: mag 10.6 size 2'.8 Position: RA 21:01 DEC +16:11
Description: At 49X and 98X surprisingly difficult for an object of 10.6 magnitude. Extremely faint. At 203X the view improved slightly and the cluster was definitly seen after a while. No resolution into stars and slightly oval in shape.
There is a sketch on this object on my homepage -- Optional related URLs: http://home.wxs.nl/~geldo006/home.html
Instrument: 51-cm other Location: Harrisburg, Pa, U.S.A.
Light pollution: light Transparency: good Seeing: good
Time: Sun Jul 6 06:00:00 1997 UT Obs. no.: 206
In addition to SS Cygni and a host of DSO's we also observed the very distant globular cluster NGC 7006 on Sunday morning. This 10.6 magnitude object was about 3' in size and unresolved. It lies some 37 kiloparsecs away.
Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "11.5M; 1' diameter; small, unresolved glow with feathered edges and bright nucleus; 40' to NNW is wide DBL ST O.Struve 213 (71" separation @ PA 037; 6.7-9.4M)."
Wildey & Sandage: pair are V=13.85/0.8 and 14.04/1.1; 1'.5 S of center;
sep 20", pa85.
POSS: pair in pa87.
15cm - faintly vis, 60x okay. f glow is 1' diam w/a rel br core. HM, Roof.
- pretty f glow. BS, 6Jun1981, Slate Mtn.
- vsm spot @ 30x. 80x shows wide m14 pair nrby on S. 140x/165x: diam ~3x
sep of m14 pair; mod sharp concen to much brtr cen. halo sl mottled,
otherwise no hint of res. BS, 12Jul1988, Anderson Mesa.
20cm - sm, fairly f. 1' diam w/unsharp cen blaze. a few f sparkles at edges,
but nothing to indicate res. FtL.
25cm - 190x, good seeing. no hint of res, 1'.25 diam, broadly brtr across
center, no sharp cen peak. S 2'.5 is wide m13 pair (15"; pa90). BS,
6Jun1981, Slate Mtn.
30cm - [L&S text] 1'.5 diam. a few f *s are res over gran bkgrnd @ 475x. CBL,
22 August 1998, Farm site, Meade 8" with a 18mm wide angle & 26mm Plossl, 36' fov, Sky Conditions: Clear 7 to 8 magnitude
Small, globular cluster resembles a wash out hazy light, getting slowly brighter to a not so bright core. Field filled with pin point stars.
16-inch f/10 SCT (184x, 290x)
Small, globular cluster resembles a wash out hazy light, getting slowly brighter to a not so bright core. Field filled with pin-point stars. It is quite a roundish haze with no stars resolved. High power show some uneven patches, but very difficult. Auke. This cluster is one of the most distant, lying in intergalactic space about 150,000 light years away. First picked up in 1784 by William Herschel.
Instrument:12-inch Dobsonian Reflector Telescope.
Sky Conditions:The fainter parts of the Milky Way are barely visible.
Transparency of the Sky:Haziness only visible on the horizon.
Seeing:Atmosphere stable with little interference.
Object Type:Globular Cluster.
First Impression:This object looks like a globular cluster.
Chart Number:No.13(Extract taken out of "Atlas of the Night Sky").
Overall Shape:Oval and strongly condensed as a faint smudge of light.The stars in this globular cluster is too faint to see.
Brightness Profile:From the central outskirts of this globular cluster it grows brighter in the nucleus.
Challenge Rating:Difficult to observe in a small telescope, but easy to observe in a large telescope under dark skies.
Are Individual stars seen? No, this globular cluster is unresolved.
How are the stars concentrated towards the nucleus? This globular cluster is very small and compact.
Estimate the size of the nucleus vs.halo? Nucleus(10.6') Halo(8.2').
Are there clumps/chains of stars? No.
Prominent empty spaces/starless patches? No.
The Messier objects
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