Star · A7V
θ Cas
θ Cas is a main-sequence star of spectral type A7V in the constellation Cassiopeia, 136.6 light-years from the Sun.
| Other names | HIP 5542 |
|---|---|
| Constellation | Cassiopeia |
| Distance | 136.6 light-years (41.9 pc) |
| Apparent magnitude | magnitude 4.34 |
| Absolute magnitude | magnitude 1.23 |
| Spectral type | A7V |
| Surface temperature | 8,400 K |
| Luminosity | 30.3 L☉ |
| Radius | 2.6 R☉ |
| Mass | 2.41 M☉ (estimated) |
| Right ascension (J2000) | 1h 11m 06.1s |
| Declination (J2000) | +55° 08′ 59″ |
| Space velocity (relative to the Sun) | 46.0 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.34). Visible from the whole Northern Hemisphere and south to latitude 35° S. North of latitude 35° 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 the year 1889. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.4 million years.
The Sun seen from there
From a planet around θ Cas, the Sun would look like a star of magnitude 7.94, in the direction where our sky has the constellation Centaurus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.