Star cluster
Trumpler 31
Open star cluster · 427 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 | Sagittarius |
| Distance | 830 pc (2.7 thousand ly) |
| Age | 427 million years |
| Member stars (MWSC) | 12 |
| Reddening E(B−V) | 0.48 |
| Source | MWSC (Kharchenko et al. 2013) |
| Right ascension (J2000) | 17h 59m 43.8s |
| Declination (J2000) | −28° 12′ 25″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 62° N. South of latitude 62° S it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 682 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 48 million years.