Star · A7IV
Alderamin
Alderamin is a subgiant star of spectral type A7IV in the constellation Cepheus, 49.0 light-years from the Sun.
| Other names | α Cep · Gl 826 · HIP 105199 |
|---|---|
| Constellation | Cepheus |
| Distance | 49.0 light-years (15.0 pc) |
| Apparent magnitude | magnitude 2.45 |
| Absolute magnitude | magnitude 1.56 |
| Spectral type | A7IV |
| Surface temperature | 7,750 K |
| Luminosity | 20.9 L☉ |
| Radius | 2.54 R☉ |
| Mass | 2.17 M☉ (estimated) |
| Right ascension (J2000) | 21h 18m 34.8s |
| Declination (J2000) | +62° 35′ 08″ |
| Space velocity (relative to the Sun) | 19.4 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 2.45). 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 August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1977. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 870 thousand years.
The Sun seen from there
From a planet around Alderamin, the Sun would look like a star of magnitude 5.72, in the direction where our sky has the constellation Carina. It would be visible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- η Cep 3.96 light-years
- 2MASS J21543318+5942187 4.76 light-years
- G 264-012 5.51 light-years
- GJ 1254 5.59 light-years
- CWISEP J213249.05+690113.7 6.61 light-years
- Gl 802 8.83 light-years
- WISE J223720.39+722833.8 10.5 light-years
- GJ 1261 10.7 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.