NGC 5694
Globular cluster in the constellation Hydra
From Wikipedia, the free encyclopedia
NGC 5694 (also known as Caldwell 66) is a globular cluster in the constellation Hydra. It was discovered by German-British astronomer William Herschel on 22 May 1784.[4]
| 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 | [Fe/H] = –1.74[3] dex |
| Estimated age | 13.44 Gyr[3] |
| Other designations | Caldwell 66 |
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[5] and is one of the oldest known globular clusters in the Milky Way Galaxy, forming nearly 12 billion years ago.[6]
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.[7]
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.
