Star · A7III
HIP 81728
HIP 81728 is a giant star of spectral type A7III in the constellation Ophiuchus, 262.2 light-years from the Sun.
| Constellation | Ophiuchus |
|---|---|
| Distance | 262.2 light-years (80.4 pc) |
| Apparent magnitude | magnitude 6.07 |
| Absolute magnitude | magnitude 1.54 |
| Spectral type | A7III |
| Surface temperature | 8,060 K |
| Luminosity | 21.9 L☉ |
| Radius | 2.4 R☉ |
| Mass | 2.19 M☉ (estimated) |
| Right ascension (J2000) | 16h 41m 36.2s |
| Declination (J2000) | −24° 28′ 05″ |
| Space velocity (relative to the Sun) | 51.8 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 6.07). Visible from the whole Southern Hemisphere and north to latitude 66° N. South of latitude 66° 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 1764. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4.7 million years.
The Sun seen from there
From a planet around HIP 81728, the Sun would look like a star of magnitude 9.36, in the direction where our sky has the constellation Taurus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 81713 2.87 light-years
- HIP 81093 15.9 light-years
- HIP 80844 17.8 light-years
- HIP 80753 18.6 light-years
- HIP 80685 18.7 light-years
- HIP 80355 19.1 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.