Star cluster
Ruprecht 43
Open star cluster · 251 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 | Puppis |
| Distance | 970 pc (3.2 thousand ly) |
| Age | 251 million years |
| Member stars (MWSC) | 57 |
| Reddening E(B−V) | 0.21 |
| Source | MWSC (Kharchenko et al. 2013) |
| Right ascension (J2000) | 7h 59m 16.8s |
| Declination (J2000) | −28° 52′ 12″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 61° N. South of latitude 61° S 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 around 1139 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 56 million years.