Star cluster
Alessi 1
Open star cluster · 692 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 | Cassiopeia |
| Distance | 750 pc (2.4 thousand ly) |
| Age | 692 million years |
| Member stars (MWSC) | 95 |
| Reddening E(B−V) | 0.10 |
| Source | MWSC (Kharchenko et al. 2013) |
| Right ascension (J2000) | 0h 53m 18.6s |
| Declination (J2000) | +49° 28′ 48″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 41° S. North of latitude 41° N it never sets. It stands highest at midnight in October, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 421 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 43 million years.