Star · K3II
σ Oph
σ Oph is a bright giant star of spectral type K3II in the constellation Ophiuchus, 867.9 light-years from the Sun.
| Other names | HIP 85355 |
|---|---|
| Constellation | Ophiuchus |
| Distance | 867.9 light-years (266.1 pc) |
| Apparent magnitude | magnitude 4.34 |
| Absolute magnitude | magnitude −2.79 |
| Spectral type | K3II |
| Surface temperature | 3,820 K |
| Luminosity | 3,930 L☉ |
| Radius | 143 R☉ |
| Mass | 9.67 M☉ (estimated) |
| Right ascension (J2000) | 17h 26m 30.9s |
| Declination (J2000) | +4° 08′ 25″ |
| Space velocity (relative to the Sun) | 28.4 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.34). Visible from the whole Northern Hemisphere and south to latitude 86° S. 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 1158. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 15 million years.
The Sun seen from there
From a planet around σ Oph, the Sun would look like a star of magnitude 11.96, in the direction where our sky has the constellation Orion. 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.