M55 · globular cluster

Messier 55

Messier 55 is a globular cluster in the south of the constellation Sagittarius.

RA19h 39m 59sDec−30° 57' 42"

Image: ESO/J. Emerson/VISTA. CC BY 4.0, via Wikimedia Commons.

Identity & coordinates

Identification

Primary designation: M55
All designations: M55 · NGC 6809
Object type: Globular Cluster
Constellation: Sagittarius
Best viewing: Summer

Coordinates & physical

Right ascension (J2000): 19h 39m 59s
Declination (J2000): −30° 57' 42"
Apparent magnitude (V): —
Distance: —

III

Visibility tonight

The science

Messier 55 is a globular cluster in the south of the constellation Sagittarius. It was discovered by Nicolas Louis de Lacaille in 1752 while observing from what today is South Africa. Starting in 1754, Charles Messier made several attempts to find this object from Paris but its low declination meant from there it rises daily very little above the horizon, hampering observation. He observed and catalogued it in 1778. The cluster can be seen with 50 mm binoculars; resolving individual stars needs a medium-sized telescope.

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