Star · B5III
ο Cas
ο Cas is a giant star of spectral type B5III in the constellation Cassiopeia, 6,375 light-years from the Sun.
| Other names | HIP 3504 |
|---|---|
| Constellation | Cassiopeia |
| Distance | 6,375 light-years (1,954 pc) |
| Apparent magnitude | magnitude 4.48 |
| Absolute magnitude | magnitude −6.98 |
| Spectral type | B5III |
| Surface temperature | 11,080 K |
| Luminosity | 86,400 L☉ |
| Radius | 79.8 R☉ |
| Mass | 2.7 M☉ (estimated) |
| Right ascension (J2000) | 0h 44m 43.5s |
| Declination (J2000) | +48° 17′ 04″ |
| Space velocity (relative to the Sun) | 182.2 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.48). Visible from the whole Northern Hemisphere and south to latitude 42° S. North of latitude 42° N it never sets. It stands highest at midnight in September, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 6,375 years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 113 million years.
The Sun seen from there
From a planet around ο Cas, the Sun would look like a star of magnitude 16.29, in the direction where our sky has the constellation Centaurus. It would be invisible to the naked eye.
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.