Globular cluster
Pal 10
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 79 % of the Sun’s. Distance, brightness and structure come from the Harris catalogue.
| Type | Globular cluster |
|---|---|
| Constellation | Sagitta |
| Distance | 5,900 pc (19.2 thousand ly) |
| Metallicity [Fe/H] | -0.10 |
| Half-light radius | 1.7 pc |
| Central concentration (c) | 0.58 |
| Radial velocity | -31.7 km/s |
| Source | Harris 1996 (2010) |
| Right ascension (J2000) | 19h 18m 02.1s |
| Declination (J2000) | +18° 34′ 18″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 71° S. North of latitude 71° N it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 19 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 341 million years.