Star · A5III
Rasalhague
Rasalhague is a giant star of spectral type A5III in the constellation Ophiuchus, 48.6 light-years from the Sun.
| Other names | α Oph · Gl 681 · HIP 86032 |
|---|---|
| Constellation | Ophiuchus |
| Distance | 48.6 light-years (14.9 pc) |
| Apparent magnitude | magnitude 2.08 |
| Absolute magnitude | magnitude 1.21 |
| Spectral type | A5III |
| Surface temperature | 8,530 K |
| Luminosity | 31.3 L☉ |
| Radius | 2.56 R☉ |
| Mass | 2.43 M☉ (estimated) |
| Right ascension (J2000) | 17h 34m 56.1s |
| Declination (J2000) | +12° 33′ 36″ |
| Space velocity (relative to the Sun) | 20.9 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 2.08). Visible from the whole Northern Hemisphere and south to latitude 77° S. North of latitude 77° N it never sets. 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 1977. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 862 thousand years.
The Sun seen from there
From a planet around Rasalhague, the Sun would look like a star of magnitude 5.70, in the direction where our sky has the constellation Lepus. It would be visible 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.