Star cluster
Alessi 10
Open star cluster · 158 million years
An open cluster of stars born together from the same gas cloud in the Milky Way’s disc; the Galaxy’s tidal forces will disperse it within a few hundred million years. Position, distance, age and member count come from the MWSC catalogue; the total brightness is roughly estimated from the member count.
| Type | Star cluster |
|---|---|
| Constellation | Aquila |
| Distance | 513 pc (1.7 thousand ly) |
| Age | 158 million years |
| Member stars (MWSC) | 45 |
| Reddening E(B−V) | 0.22 |
| Source | MWSC (Kharchenko et al. 2013) |
| Right ascension (J2000) | 20h 04m 43.7s |
| Declination (J2000) | −10° 29′ 06″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 80° N. South of latitude 80° S 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 around the year 353. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 30 million years.