Star · K2III
Arcturus
Arcturus is a giant star of spectral type K2III in the constellation Boötes, 36.7 light-years from the Sun.
| Other names | α Boo · Gl 541 · HIP 69673 |
|---|---|
| Constellation | Boötes |
| Distance | 36.7 light-years (11.3 pc) |
| Apparent magnitude | magnitude −0.05 |
| Absolute magnitude | magnitude −0.31 |
| Spectral type | K2III |
| Surface temperature | 4,230 K |
| Luminosity | 257 L☉ |
| Radius | 29.8 R☉ |
| Mass | 4.43 M☉ (estimated) |
| Right ascension (J2000) | 14h 15m 39.7s |
| Declination (J2000) | +19° 10′ 57″ |
| Space velocity (relative to the Sun) | 121.7 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude −0.05). Visible from the whole Northern Hemisphere and south to latitude 71° S. North of latitude 71° N it never sets. It stands highest at midnight in April, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1989. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 651 thousand years.
The Sun seen from there
From a planet around Arcturus, the Sun would look like a star of magnitude 5.09, in the direction where our sky has the constellation Cetus. 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.