Star · B7IV
Alnair
Alnair is a subgiant star of spectral type B7IV in the constellation Grus, 101.0 light-years from the Sun.
| Other names | α Gru · Gl 848.2 · HIP 109268 |
|---|---|
| Constellation | Grus |
| Distance | 101.0 light-years (31.0 pc) |
| Apparent magnitude | magnitude 1.73 |
| Absolute magnitude | magnitude −0.72 |
| Spectral type | B7IV |
| Surface temperature | 11,090 K |
| Luminosity | 274 L☉ |
| Radius | 4.48 R☉ |
| Mass | 4.51 M☉ (estimated) |
| Right ascension (J2000) | 22h 08m 14.0s |
| Declination (J2000) | −46° 57′ 40″ |
| Space velocity (relative to the Sun) | 30.6 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 1.73). Visible from the whole Southern Hemisphere and north to latitude 43° N. South of latitude 43° S 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 1925. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.8 million years.
The Sun seen from there
From a planet around Alnair, the Sun would look like a star of magnitude 7.28, in the direction where our sky has the constellation Ursa Major. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- Gl 847.1 4.24 light-years
- GJ 4245 8.85 light-years
- 2MASSW J2206450-421721 9.44 light-years
- HIP 107865 10.8 light-years
- WISEAR J220746.67-503631.7 12.0 light-years
- HIP 110468 12.6 light-years
- HIP 109421 13.2 light-years
- Gl 836.3 13.4 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.