Star · B2III
Alfirk
Alfirk is a giant star of spectral type B2III in the constellation Cepheus, 685.2 light-years from the Sun.
| Other names | β Cep · HIP 106032 |
|---|---|
| Constellation | Cepheus |
| Distance | 685.2 light-years (210.1 pc) |
| Apparent magnitude | magnitude 3.23 |
| Absolute magnitude | magnitude −3.38 |
| Spectral type | B2III |
| Surface temperature | 13,610 K |
| Luminosity | 4,780 L☉ |
| Radius | 12.4 R☉ |
| Mass | 10.2 M☉ (estimated) |
| Right ascension (J2000) | 21h 28m 39.6s |
| Declination (J2000) | +70° 33′ 39″ |
| Space velocity (relative to the Sun) | 17.2 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 3.23). Visible from the whole Northern Hemisphere and south to latitude 19° S. North of latitude 19° 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 1341. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 12 million years.
The Sun seen from there
From a planet around Alfirk, the Sun would look like a star of magnitude 11.44, in the direction where our sky has the constellation Carina. 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.