Star · A7III
θ Cep
θ Cep is a giant star of spectral type A7III in the constellation Cepheus, 138.9 light-years from the Sun.
| Other names | HIP 101093 |
|---|---|
| Constellation | Cepheus |
| Distance | 138.9 light-years (42.6 pc) |
| Apparent magnitude | magnitude 4.21 |
| Absolute magnitude | magnitude 1.06 |
| Spectral type | A7III |
| Surface temperature | 8,170 K |
| Luminosity | 34.5 L☉ |
| Radius | 2.93 R☉ |
| Mass | 2.5 M☉ (estimated) |
| Right ascension (J2000) | 20h 29m 34.8s |
| Declination (J2000) | +62° 59′ 39″ |
| Space velocity (relative to the Sun) | 10.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.21). Visible from the whole Northern Hemisphere and south to latitude 27° S. North of latitude 27° N it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1887. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.5 million years.
The Sun seen from there
From a planet around θ Cep, the Sun would look like a star of magnitude 7.98, in the direction where our sky has the constellation Carina. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- 4 Cep 9.77 light-years
- HIP 104788 12.3 light-years
- HIP 105992 17.4 light-years
- 68 Dra 18.0 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.