Star · A7IV
Altair
Altair is a subgiant star of spectral type A7IV in the constellation Aquila, 16.7 light-years from the Sun.
| Other names | α Aql · Gl 768 · HIP 97649 |
|---|---|
| Constellation | Aquila |
| Distance | 16.7 light-years (5.13 pc) |
| Apparent magnitude | magnitude 0.76 |
| Absolute magnitude | magnitude 2.21 |
| Spectral type | A7IV |
| Surface temperature | 8,000 K |
| Luminosity | 11.8 L☉ |
| Radius | 1.79 R☉ |
| Mass | 1.85 M☉ (estimated) |
| Right ascension (J2000) | 19h 50m 47.0s |
| Declination (J2000) | +8° 52′ 06″ |
| Space velocity (relative to the Sun) | 31.0 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 0.76). Visible from the whole Northern Hemisphere and south to latitude 81° S. 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 2009. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 297 thousand years.
The Sun seen from there
From a planet around Altair, the Sun would look like a star of magnitude 3.38, in the direction where our sky has the constellation Monoceros. It would be visible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HD 180617 3.85 light-years
- Gl 752B 3.86 light-years
- WISE J192841.35+235604.9 7.72 light-years
- Gl 702B 7.78 light-years
- 70 Oph 7.78 light-years
- WISEPC J205628.90+145953.3 8.01 light-years
- Gl 791.2 8.37 light-years
- HIP 103039 9.21 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.