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Entire DOCdb database of 18,816 objects.



NGC 4590 (9,980 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




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Messier 68

NGC 4590, Cl Melotte 113, C 1236-264, GCl 20, HD 110032, Messier 68, Bennett 51, h 3404, GC 3128

RA: 12h 39m 28.01s
Dec: −26° 44′ 34.9″

Con: Hydra
Ch: MSA:869, U2:329, SA:21


(reference key)

Type: globular cluster

Mag: B=10.26, V=9.67

Size: 11′
PA: ?

Historical observations

William Herschel (c.1784)

In the Philosophical Transactions, 1814, William Herschel described it as "a beautiful cluster of stars, extremely rich, and so compressed that most of the stars are blended together; it is near 3' broad and about 4' long, but chiefly round, and there are very few scattered stars about. This oval cluster is also approaching to the globular form, and the central compression is carried to a high degree. The insulation is likewise so far advanced that it admits of an accurate description of the contour. The clusters of this class are beautiful, but can hardly be seen to any advantage without a 20 feet telescope." In the Philosophical Transactions, 1818, William Herschel wrote: "1786, 1789, 1790, 20 feet telescope. A cluster of very compressed small stars, about 3' broad and 4' long. The stars are so compressed, that most of them are blended together."

John Herschel (1847) Cape Observations

Observed by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "globular, irregularly round, gbM, diam in RA = 12..15 seconds. All clearly resolved into stars 12th mag; very loose and ragged at the borders."

Published comments

Helwan Obs. Bulletin No 9 (1912)

Globular cluster, 4' in diameter, rahter irregular, slightly condensed.

Bailey, S.I. (1908)

"! globular cluster, fairly condensed"

Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.

Melotte, P.J. (1915)

A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 9.0 mag globular cluster.

Harris, W.E. (1997)

RA 12 39 28.0 (2000) Dec -26 44 34 Integrated V magnitude 7.84 Central surface brightness, V magnitudes per square arcsecond 18.67 Integrated spectral type F2/3 Central concentration, c = log(r_total/r_core); a 'c' denotes a core-collapsed cluster 1.64 Core radius in arcmin .69. ["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) ]

Doig, P. (1925)

Doig, P. (1925) Notes on the nebulae and clusters in Webb's 'Celestial Objects for Common Telescopes' (Sixth edition, Vol.ii). Part II. M.N.R.A.S., 35(8), 280.

Modern observations

Hartung, E.J. (1968) Astron.Obj.South.Tel

Hartung notes: "Faint outliers may be detected with 10.5cm. It is very rich, broadly concentrated to a central region about 2' across and the outlying stars show evidence of a spiral pattern 5' - 6' across. 15cm resolves this cluster clearly though faintly."

Walter Scott Houston

Houston includes this globular in his Hydra Hysteria. He calls it "beautiful" and notes that "individual stars should be easily visible in a 6-inch scope." In 1972 he called it one of two globulars worth-while looking up in Hydra (the other being NGC 5694). He notes that it shines at 8th mag: "since its stars are 12th mag and fainter, a large scope is needed to discern them. Visually, M68 appears about 3' in diameter. Observing with a 6-inch refractor, Smyth described this globular as oval, pale and mottled."

Steve Coe

Steve Coe (1992, The Deep-Sky Observer, Webb Society, Issue 1) observing with a 17.5-inch f/4.5 at 100x notes: "pB, rich, compressed, seen in finder. Resolved at all powers. 'Kidney-shaped' with streamers on one side. About 50 stars resolved at 165x. Many stars at the limit of the 17.5-inch, averted vision makes it grow. At 300x the core has about 10 stars resolved and the central area is very grainy. Entire cluster looks like a garden sprinkler, with eF stars seen as a set of curved chains that exit the main body and swirl around."

Tom Lorenzin

Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "8M; 9' diameter; well resolved into glitter of 13M stars; 33' to SW lies bright DBL ST ADS 8612."

Ware, Donald J

"This rather bright globular cluster is about 8-10' in diameter and is very compact, showing a bright, granulated core and many stars resolved around its edges."

Steve Coe

Steve Coe, observing with a 17.5" f/4.5 at 100X, notes: "Pretty bright, Rich, Compressed, seen in finder. Resolved at all powers. "Kidney-shaped" with steamers on one side. About 50 stars resolved at 165X. Many stars at the limit of 17.5", averted vision makes it grow. At 300X the core has about 10 stars resolved and the central area is very grainy. Entire cluster looks like a garden sprinkler, with extremely faint stars seen as a set of curved chains that exit the main body and swirl around. Sentinel 13" 8/10-- bright, large, extremely rich, extrememly compressed, bright middle, irregularly round, stars 13th mag and less. Easy in 11X80, very comet-like in finder. 330X--20 stars resolved, several nice chains, curved edges are ragged at high power.

Brian Skiff

= M68

7x35mm - mod f, sm, mod concen. BS, 28May1995, TSP.

15cm - unres @ 100x. a few outliers, speckled, unconcen, tantalizing.

25cm - lg and fairly br. 10' diam and gran @ 44x. 112x: res clear across the

cen w/underlying haze. circ, no irregs noted.

30cm - 10' diam. cottony center 3' across @ 238x. 50 or 60 *s seen. center

*s br, brtst being S of cen.

Harrington, Phil (1986)

Harrington, P. (1986) More globulars for observers. Sky&Telescope, Sep, 310.

".. the cluster can be partially resolved with a 6-incht elescope.."

Danie L. Cronje


Danie Cronje, observing with 10x50 binoculars, calls it a "faint, small, round glow. Almost stellar core. Near a rather bright star."

Contemporary observations

Magda Streicher

2010 February 12

Location: Alldays

12-inch f/10 SCT (218x)

Outstanding bright haze well outstanding against the background star field. But, it is by far not easy to resolve this globular cluster. However with high power only a few pin-point stars can be seen. The more you try to re focus the object the less you can see. The core is very much obscure with faint mist indicate a rich cluster.

1997 June 7

Nice bright cluster dense middle. Faint Stars just reveal themselfes,With startrails spreading out towards the edges. Fairly round. Standing out to the backround. Few stars in field.

Chris Vermeulen

2007 June 09

2007/6/9, 17h58

Sky Conditions: Clear

Quality of Observation: Very Good

Bill Hollenbach's Pad

6" Dobsonian, 25mm Eyepiece

M68 is a beautiful globular cluster in the constellation of Hydra. The most interestingly appearance is the blue-ish colour of its disc when viewed through a 25 mm eyepiece. Not visible to the naked eye, but through a 25mm eyepiece this significantly globular cluster's core is rather dense and it glows very brightly. Towards the outer edges stars are scattered loosely around the object itself almost giving the impression of a halo-effect.

Magda Streicher

2010 February 12

Location: Alldays

12-inch f/10 SCT (218x)

Outstanding bright haze well outstanding against the background star field. But, it is by far not easy to resolve this globular cluster. However with high power only a few pin-point stars can be seen. The more you try to re focus the object the less you can see. The core is very much obscure with faint mist indicate a rich cluster.

(no date)

12-inch f/10 SCT (EP: 2-inch 40mm SW 76x 53' fov; 2-inch 14mm UW 218x 23' fov)

A nice bright and large globular cluster, with a compressed core. A multitude of stars clearly reveals themselves in the outer halo with faint star trails spreading out from the edges. Standing out beautifully against the background with a few speckled stars in the field. Observed again with (218x) the globular appears somewhat oval in a northeast to southwest direction. I suspect that the lengthy appearance might be attributed to the fact that there are more star clumps at the two sides mentioned. Faint pinpoint stars group more visibly to the north west of the globular. (Mag 7.8; size 12.0')

Richard Ford

2015, February, 23rd



Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.

Instrument:12-inch Dobsonian.

This globular clusters shape has the resemblance of a moderately condensed snowball at 75x.In overall the stars in this cluster is well resolved and that the central nucleus of M68 is strongly concentrated towards each other.This globular cluster measures 9.7'x 7.4'.Chart No.218,NSOG Vol.2.

2009 March 21


12-inch Dobsonian f5 (EP: 20mm UW, 7mm UW)

Conditions: The fainter parts of the Milky Way are barely visible. Haziness only visible on the horizon. Atmosphere stable with little interference. Limiting Magnitude: 4.9.

Messier 68 is a very bright globular cluster that has a large oval appearance of bright stars radiating away from the outskirts. It is easy to observe in city skies and is a spectacular sight in dark skies. The cluster is well-resolved into bright individual stars radiating away from the central structure. The nucleus measures 18' and the halo measures 10'. There are chains of stars in the central outskirts of this cluster, and there are some starless patches in the central outskirts of this cluster.

Tom Bryant

2008-05-28 23:00:00

Observing site: Pinnacles overlook

Telescope: C-8

[12h 39m 30s, -26 45' 0"] A globular cluster, 3' in diameter. Approximately 50 stars were seen with averted vision, 5-10 with direct. This suggests that my averted vision is reaching 14.5 mv, direct 13th.

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