NGC 5694

NGC 5694 (also known as Caldwell 66) is a globular cluster in the constellation Hydra. It was discovered in 1784 by William Herschel.

NGC 5694
The core of NGC 5694 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
Class	VII[1]
Constellation	Hydra
Right ascension	14h 39m 36.5s[2]
Declination	−26° 32′ 18.0″[2]
Distance	114,100ly[1]
Apparent magnitude (V)	10.2[1]
Apparent dimensions (V)	3.6′[1]
Physical characteristics
Metallicity	${\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}$ = –1.74[3] dex
Estimated age	13.44 Gyr[3]
Other designations	Caldwell 66
See also: Globular cluster, List of globular clusters

Characteristics

This globular cluster is located at a distance of 114,000 light-years (35,000 pc) from the Sun and 96,000 light-years (29,000 pc) from the Galactic Center^[4] and is one of the oldest known globular clusters in the Milky Way Galaxy, forming nearly 12 billion years ago.^[5]

Its chemical composition is highly peculiar, being highly (to nearly solar levels) enriched in alpha elements, suggesting an extragalactic origin before being captured by the Milky Way.^[6]

Noctua

NGC 5694 is located below the tail of the former constellation Noctua, which included faint stars within the modern IAU borders of Libra, Hydra, and Virgo.

See also

• NGC 4372