Star · K5III
81 Aqr
81 Aqr is a giant star of spectral type K5III in the constellation Aquarius, 457.3 light-years from the Sun.
| Other names | HIP 113674 |
|---|---|
| Constellation | Aquarius |
| Distance | 457.3 light-years (140.2 pc) |
| Apparent magnitude | magnitude 6.23 |
| Absolute magnitude | magnitude 0.50 |
| Spectral type | K5III |
| Surface temperature | 3,920 K |
| Luminosity | 170 L☉ |
| Radius | 28.2 R☉ |
| Mass | 3.94 M☉ (estimated) |
| Right ascension (J2000) | 23h 01m 23.6s |
| Declination (J2000) | −7° 03′ 40″ |
| Space velocity (relative to the Sun) | 12.0 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 6.23). Visible from the whole Southern Hemisphere and north to latitude 83° N. It stands highest at midnight in September, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1569. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 8.1 million years.
The Sun seen from there
From a planet around 81 Aqr, the Sun would look like a star of magnitude 10.56, in the direction where our sky has the constellation Leo. It would be invisible to the naked eye.
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.