Star · K0III
HIP 21685
HIP 21685 is a giant star of spectral type K0III in the constellation Eridanus, 209.5 light-years from the Sun.
| Constellation | Eridanus |
|---|---|
| Distance | 209.5 light-years (64.2 pc) |
| Apparent magnitude | magnitude 5.46 |
| Absolute magnitude | magnitude 1.42 |
| Spectral type | K0III |
| Surface temperature | 4,620 K |
| Luminosity | 39 L☉ |
| Radius | 9.77 R☉ |
| Mass | 2.59 M☉ (estimated) |
| Right ascension (J2000) | 4h 39m 19.7s |
| Declination (J2000) | −14° 21′ 33″ |
| Space velocity (relative to the Sun) | 79.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 5.46). Visible from the whole Southern Hemisphere and north to latitude 76° N. South of latitude 76° 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 1816. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 3.7 million years.
The Sun seen from there
From a planet around HIP 21685, the Sun would look like a star of magnitude 8.87, 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 22002 13.9 light-years
- HIP 21329 17.5 light-years
- HIP 21705 19.6 light-years
- HIP 21220 19.7 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.