Star · F2III
HIP 81657
HIP 81657 is a giant star of spectral type F2III in the constellation Ara, 104.0 light-years from the Sun.
| Constellation | Ara |
|---|---|
| Distance | 104.0 light-years (31.9 pc) |
| Apparent magnitude | magnitude 6.17 |
| Absolute magnitude | magnitude 3.65 |
| Spectral type | F2III |
| Surface temperature | 6,440 K |
| Luminosity | 2.97 L☉ |
| Radius | 1.38 R☉ |
| Mass | 1.31 M☉ (estimated) |
| Right ascension (J2000) | 16h 40m 50.4s |
| Declination (J2000) | −60° 26′ 47″ |
| Space velocity (relative to the Sun) | 14.7 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 6.17). Visible from the whole Southern Hemisphere and north to latitude 30° N. South of latitude 30° S it never sets. It stands highest at midnight in May, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1922. 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 HIP 81657, the Sun would look like a star of magnitude 7.35, in the direction where our sky has the constellation Camelopardalis. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.