Globular Cluster Messier 68

Messier 68: Image taken with Hubble Space Telescope. © ESA/Hubble & NASA [245]

History

The globular cluster M 68 was discovered on 9th April 1780 by Charles Messier, who wrote: «Nebula without stars under the raven and the water snake; it is very weak, very difficult to see with the telescope; next to it is a star 6th magnitude.» [281] Wilhelm Herschel wrote: «A beautiful star cluster, extremely rich and so compressed that most of the stars are mixed together. it is nearly 3' wide and about 4' long, but mostly round, and there are very few stars scattered around.» [217]

Physical Properties

The distance from M 68 is about 10.3 kpc (33'600 light years) and it is moving towards us at about 93 km/s. The mass is 223'000 times that of the sun. [251] 50 variables were found in the star cluster. [282] [282]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
DesignationNGC 4590
TypeGCL (X)
Right Ascension (J2000.0)12h 39m 28.0s
Declination (J2000.0)-26° 44' 32"
Diameter11 arcmin
Visual magnitude7.3 mag
Metric Distance10.300 kpc
Dreyer Descriptionglobular, L, eRi, vC, iR, rrr, st 12
Identification, RemarksM 68, GCL 20, ESO 506-SC30

Galaxy PGC 42334

The small, faint galaxy PGC 42334 is only about 10 arc minutes away.

«Catalogue of Principal Galaxies» Paturel et al., 1989 [144]
DesignationsPGC 42334: ESO 506-29, MCG 4-30-9
Right Ascension (J2000.0)12h 39m 16.3s
Declination (J2000.0)-26° 54' 41"
Morphological TypeSB
Dimensions1.2' x 1.1'
Visual Magnitude14.2 mag
Radial Velocity (HRV)2976 km/s
Position Angle°

Finder Chart

M 68 lies in the constellation Hydra. To find it, connect the stars Algorab (η Corvi) - Kraz (β Corvi) by 3.5 ° to the south. It is best seen from February to May.

Finder Chart Globular Cluster Messier 68
Globular Cluster Messier 68 in constellation Hydra. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Visual Observation

Description pending ...

More Objects Nearby (±20°)

References