Globular cluster
E 1 (AM 1)
Globular cluster
A globular cluster of hundreds of thousands of old stars orbiting in the Galaxy’s halo: among the oldest objects of the Milky Way, about 12 billion years old. Its metal abundance is 2.0 % of the Sun’s. Distance, brightness and structure come from the Harris catalogue.
| Type | Globular cluster |
|---|---|
| Constellation | Horologium |
| Distance | 123,300 pc (402.2 thousand ly) |
| Metallicity [Fe/H] | -1.70 |
| Half-light radius | 14.7 pc |
| Central concentration (c) | 1.36 |
| Radial velocity | 116.0 km/s |
| Source | Harris 1996 (2010) |
| Right ascension (J2000) | 3h 55m 02.3s |
| Declination (J2000) | −49° 36′ 55″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 40° N. South of latitude 40° S it never sets. It stands highest at midnight in November, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 402 thousand years ago. At that time our ancestors were using stone tools; Homo sapiens did not exist yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 7.1 billion years.