sponsored by psychohistorian.org
RA: 18h 45m 18s
Dec: −09° 23′ 0″
Ch: MSA:1342, U2:295, SA:16
Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003)
Type: open cluster, 23m
Mag: B=8, V=8.87
Select a sketch and click the button to view
Select a photo and click the button to view
In the Appendix to the 1912 'Scientific Papers of Sir William Herschel' this object is described as "1784, June 16, 20 feet telescope, a cluster of scattered stars, not rich."
Observed by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "Cluster VII class, p rich, irreg R, p well insulated, not much comp M; 10' diam; stars 12..15m, one 9m taken."
Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 9' and the class as 2 2 m.
Doig, P. (1925) Notes on the nebulae and clusters in Webb's 'Celestial Objects for Common Telescopes' (Sixth edition, Vol.ii). Part IV. M.N.R.A.S., 36(2), 58.
The RNGC (Sulentic and Tifft 1973) notes that this is a 9.5 mag open cluster.
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 7.66
Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
Raab, S. (1922) A research on open clusters. Lund Medd. Astron. Obs. Ser. II, 28, 1.
Discussed, based of F-A plates.
A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.
John Bortle (Webb Society Quarterly Journal, January 1976) using 10x50 binoculars, estimates the visual magnitude as 7.7.
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "9.5M; 9' diameter; sparse and dull; 30-plus 11 thru 14M members; zzzzzz! when snooze is over, try it in binoculars."
Hoag: br * on SW.
7x35mm - sm mod concen spot w/f sharp center. BS, 29Apr1992, TSP.
7cm - mod br w/br * on W edge @ 30x. lies nr W edge of *cloud where density and bkgrnd brtness drops off. 75x: 15 *s res w/mod concen. isolated * on NE. BS, 23Jun1996, Mars Hill.
8cm - easy @ 20x. br * on SE consp. partially res. BS, 13Sep1982, Anderson Mesa.
15cm - compact cl of 20 *s in 7' area. one br *, rest m11+. BS, 28Mar1971, FtL.
- sl haze, four *s in shield-shape distinguish it from fld. HM, Roof.
- 20 *s, nice cl. BS, 15Mar1981, Anderson Mesa.
- must be fntst Messier oc, even though mod rich. m9.5 * on W side of 6' cl. rest of *s m11.5+. 140x shows 40 *s incl m12 pair (aligned N-S) ~2' E of brtst. fld rel blank on W side; SW is wide m11.5 pair. BS, 21Jun1990, Anderson Mesa.
25cm - 180x: 8' diam. br * on SW. gaping hole in N side. 35 *s. BS,
- pretty nice, m9 * on W side. 190x gives 5' diam, a little concen. about 35 *s incl a few close pairs. BS, 15Mar1981, Anderson Mesa.
30cm - 8' diam. loose and brtr *s on SW. on NW is arc of *s and `dipper' nr center. CBL, Roof.
(IAAC) Obj: M26 (NGC 6694) - Inst: 12.5" f/6.5 Cave equatorial Newtonian
Observer: Dave Mitsky
Your skills: Intermediate (some years)
Date/time of observation: 6/18/98 06:30 UT
Location of site: Naylor Observatory http://www.msd.org/obs.htm (Lat 40.1d N, 76.9d W, Elev 570')
Site classification: Exurban
Sky darkness: ~5.0 Limiting magnitude
Seeing: 8 1-10 Seeing Scale (10 best)
Moon presence: None - moon not in sky
Instrument: 12.5" f/6.5 Cave equatorial Newtonian
Magnification: 65x, 121x, 159x
Object(s): M26 (NGC 6694)
Category: Open cluster.
Class: I 1 m
Data: mag 8.0 size 15.0'
Position: RA 18:45.2 DEC -09:24
M26 is a large but detached open cluster consisting of 30 stars that have a central concentration. It is about 16 light years in size, is 89 million years old, and is about 4900 light years distant.
To me M26 (along with M29) is one of the least impressive of the Messier open clusters. At 65x it was barely noticeable among the many stars of Scutum. Using a 13mm Tele Vue Ploessl allowed me to see about a dozen faint stars in addition to the 4 moderately bright ones that are more readily apparent.
Steve Coe, observing with a 17.5" f/4.5 at 100X, notes: " (M 26) Bright, pretty rich, little compressed. Easy in the 8 X 50 finder, the smaller Instrument shows why Messier included it. I counted 20 stars in a wishbone shape using the 13" at 100X.
In a 15.5-inch at 220X, this is a most remarkable object! It is a splendid example of the diversity of deepsky objects. The structure and organization the mind imposes on this grouping of stars is extraordinary. Overall, the cluster lies elongated NNE to SSE, and has one prominent white member. There are three fainter stars, the rest of the cluster members being quite a bit fainter. The striking feature of the cluster is its fragmentation: it is broadly divided into two parts by a dark band running NNE-SSW along the major axis of the cluster. At the north end, the dark band splits into two branches, forming a Yshaped void. The eastern arm of the Y divides this section of the cluster into two: The northern segment is triangular in shape, with one of the brighter stars at its apex, nearest the junction. The more southern section, although it contains two of the brighter stars, is less prominently delineated and fades raggedly away to the east and south. The portion to the west of the dark gulf contains, in the south, the brightest star, white in colour, whilst the northern part consists of a tight knot of stars with a prominent curved chain of 5 stars arcing to the south-west. The south-south-west end of the main cluster body ends in a barren black patch with only 1 small isolated star. Just south of this lone star is a semi-circle of 5 stars, which seems to round off the dark dividing lane.
1995 May 26, 03:00. 11x80 binoculars. Looks like a small but bright globular cluster.
1995-06-01: 11x80. Kelsey Farm. 23:00 SAST. Quite small, reasonably bright globular cluster. Certainly doesn't look like an open cluster in binoculars.
1997 July 6, Sunday, 21:00 - 23:00 Jonkershoek. 11x80's tripod-mounted. Looks like a fuzzy globular cluster. Perhaps slighly elongated?
1997 July 8, Tuesday, 20:55 - 23:30 Jonkershoek. 11x80's tripod-mounted. Globular. Seems more concentrated on the southern side. Smaller than shown on the map.
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:Open Cluster.
First Impression:This object looks like an open cluster.
Chart Number:No.12(Extract taken out of "Atlas of the Night Sky").
Size:26mm Eyepiece:Field Of View:57'/9=6.3'.
20mm Eyepiece:Field Of View:50'/8=6.2'.
Size in Arc Minutes:6.2'.
Open Cluster is 6.2'*2.0'.
Brightness Profile:From the far outskirts of this cluster it grows slightly brighter.
This open cluster is well detached and the stars are of 7th to 9th magnitude.I have counted 42 stars within a fixed diameter.Most of the stars in this cluster are not at all separated.In this cluster bright and faint stars are mixed together.Around some areas of this cluster there is some slight starless patches.
The Messier objects
The Bennett objects
The Caldwell list
DOCdb is still in beta-release.
Known issues, feature requests, and updates on bug fixes, are here:
Found a bug? Have a comment or suggestion to improve DOCdb? Please let us know!
DOCdb is a free online resource that exists to promote deep sky observing.
You could help by sharing your observations, writing an article, digitizing and proof-reading historical material, and more.
Everything on DOCdb.net is © 2004-2010 by Auke Slotegraaf, unless stated otherwise or if you can prove you have divine permission to use it. Before using material published here, please consult the Creative Commons Attribution-Non-Commercial-Share Alike 2.5 License. Some material on DOCdb is copyright the individual authors. If in doubt, don't reproduce. And that goes for having children, too. Please note that the recommended browser for DOCdb is Firefox 3.x. You may also get good results with K-Meleon. Good luck if you're using IE. A successful experience with other browsers, including Opera and Safari, may vary.