Star
The brightest star in the northern celestial hemisphere, an aging orange giant nearing the end of its life.
| Type | Star |
|---|---|
| Distance from Earth | 36.7 ly |
| Diameter | 36,500,000 km |
| Mass | 2.15 × 10³⁰ kg |
| Temperature | 4,013°C |
| Apparent magnitude | -0.05 |
| Redshift | 0 |
| Hemisphere | Northern |
| Discovered | 150 |
Stars spend most of their lives fusing hydrogen into helium in their core, and it's the balance between that outward pressure and gravity pulling inward that fixes how big and how bright a star gets.
At 36,500,000 km across, Arcturus is 26 times the diameter of the Sun.
Its mass is 1.1 times the mass of the Sun.
The light reaching us from Arcturus tonight left it around 37 years ago.
Its surface sits at 4,286 K, cooler than the Sun at 5,772 K, which is what sets its colour.
It has been on record since the year 150.
Play today's Cosmodle