Globular cluster
Ko 2
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. Distance, brightness and structure come from the Harris catalogue.
| Type | Globular cluster |
|---|---|
| Constellation | Gemini |
| Distance | 34,700 pc (113.2 thousand ly) |
| Half-light radius | 2.1 pc |
| Central concentration (c) | 0.50 |
| Source | Harris 1996 (2010) |
| Right ascension (J2000) | 7h 58m 17.0s |
| Declination (J2000) | +26° 15′ 18″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 64° S. North of latitude 64° N it never sets. It stands highest at midnight in January, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 113 thousand years ago. At that time Homo sapiens was spreading out of Africa; there was no farming yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.0 billion years.