M12 · globular cluster

Messier 12

Messier 12 or M 12 is a globular cluster in the constellation of Ophiuchus.

RA16h 47m 14sDec−01° 56' 51"

Image: ESA/Hubble & NASA. Public domain, via Wikimedia Commons.

Identity & coordinates

Identification

Primary designation: M12
All designations: M12 · NGC 6218
Object type: Globular Cluster
Constellation: Ophiuchus
Best viewing: Summer

Coordinates & physical

Right ascension (J2000): 16h 47m 14s
Declination (J2000): −01° 56' 51"
Apparent magnitude (V): —
Distance: —

III

Visibility tonight

The science

Messier 12 or M 12 is a globular cluster in the constellation of Ophiuchus. It was discovered by the French astronomer Charles Messier on May 30, 1764, who described it as a "nebula without stars". In dark conditions this cluster can be faintly seen with a pair of binoculars. Resolving the stellar components requires a telescope with an aperture of 8 in (20 cm) or greater. In a 10 in (25 cm) scope, the granular core shows a diameter of 3′ (arcminutes) surrounded by a 10′ halo of stars.

Summary adapted from Wikipedia · CC-BY-SA-4.0