Star · K2III
23 Oph
23 Oph is a giant star of spectral type K2III in the constellation Ophiuchus, 254.0 light-years from the Sun.
| Other names | HIP 82730 |
|---|---|
| Constellation | Ophiuchus |
| Distance | 254.0 light-years (77.9 pc) |
| Apparent magnitude | magnitude 5.23 |
| Absolute magnitude | magnitude 0.77 |
| Spectral type | K2III |
| Surface temperature | 4,510 K |
| Luminosity | 75.9 L☉ |
| Radius | 14.2 R☉ |
| Mass | 3.13 M☉ (estimated) |
| Right ascension (J2000) | 16h 54m 35.7s |
| Declination (J2000) | −6° 09′ 14″ |
| Space velocity (relative to the Sun) | 19.9 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 5.23). Visible from the whole Southern Hemisphere and north to latitude 84° N. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1772. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4.5 million years.
The Sun seen from there
From a planet around 23 Oph, the Sun would look like a star of magnitude 9.29, in the direction where our sky has the constellation Orion. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 82537 3.23 light-years
- HIP 81952 15.2 light-years
- HIP 83146 17.5 light-years
- HIP 82626 17.7 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.