Star · A0V
HIP 21644
HIP 21644 is a main-sequence star of spectral type A0V in the constellation Eridanus, 229.1 light-years from the Sun.
| Constellation | Eridanus |
|---|---|
| Distance | 229.1 light-years (70.3 pc) |
| Apparent magnitude | magnitude 4.99 |
| Absolute magnitude | magnitude 0.76 |
| Spectral type | A0V |
| Surface temperature | 9,290 K |
| Luminosity | 52.7 L☉ |
| Radius | 2.8 R☉ |
| Mass | 2.82 M☉ (estimated) |
| Right ascension (J2000) | 4h 38m 53.6s |
| Declination (J2000) | −12° 07′ 23″ |
| Space velocity (relative to the Sun) | 21.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.99). Visible from the whole Southern Hemisphere and north to latitude 78° N. South of latitude 78° S it never sets. It stands highest at midnight in November, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1797. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4.1 million years.
The Sun seen from there
From a planet around HIP 21644, the Sun would look like a star of magnitude 9.06, in the direction where our sky has the constellation Hercules. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 21595 9.75 light-years
- HIP 21705 9.91 light-years
- HIP 22002 10.0 light-years
- HIP 20854 17.6 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.