Star · B3IV
Azelfafage
Azelfafage is a subgiant star of spectral type B3IV in the constellation Cygnus, 1,435 light-years from the Sun.
| Other names | π¹ Cyg · HIP 107136 |
|---|---|
| Constellation | Cygnus |
| Distance | 1,435 light-years (440.0 pc) |
| Apparent magnitude | magnitude 4.69 |
| Absolute magnitude | magnitude −3.53 |
| Spectral type | B3IV |
| Surface temperature | 11,900 K |
| Luminosity | 4,140 L☉ |
| Radius | 15.1 R☉ |
| Mass | 9.81 M☉ (estimated) |
| Right ascension (J2000) | 21h 42m 05.7s |
| Declination (J2000) | +51° 11′ 23″ |
| Space velocity (relative to the Sun) | 15.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.69). Visible from the whole Northern Hemisphere and south to latitude 39° S. North of latitude 39° 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 591. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 25 million years.
The Sun seen from there
From a planet around Azelfafage, the Sun would look like a star of magnitude 13.05, in the direction where our sky has the constellation Vela. 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.