Star · K3III
Alphard
Alphard is a giant star of spectral type K3III in the constellation Hydra, 180.3 light-years from the Sun.
| Other names | α Hya · HIP 46390 |
|---|---|
| Constellation | Hydra |
| Distance | 180.3 light-years (55.3 pc) |
| Apparent magnitude | magnitude 1.99 |
| Absolute magnitude | magnitude −1.72 |
| Spectral type | K3III |
| Surface temperature | 3,890 K |
| Luminosity | 1,370 L☉ |
| Radius | 81.6 R☉ |
| Mass | 7.15 M☉ (estimated) |
| Right ascension (J2000) | 9h 27m 35.2s |
| Declination (J2000) | −8° 39′ 31″ |
| Space velocity (relative to the Sun) | 10.8 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 1.99). Visible from the whole Southern Hemisphere and north to latitude 81° N. It stands highest at midnight in February, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1846. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 3.2 million years.
The Sun seen from there
From a planet around Alphard, the Sun would look like a star of magnitude 8.54, in the direction where our sky has the constellation Pegasus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 46203 6.04 light-years
- HIP 47050 10.1 light-years
- HIP 47040 10.5 light-years
- SIMP J09455513-0757441 15.7 light-years
- HIP 46744 16.4 light-years
- HIP 46543 16.4 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.