Cosmic Scale
Spica
Blue giant (binary) · 250 light-years
How big is Spica?
Spica is about 1.0 × 10⁷ km across.
See Spica in 3D, at true scale
Spica, the brightest star in Virgo, is really two hot blue stars orbiting each other every four days, so close that each is pulled into an egg shape by the other.
At a glance
| Diameter | 1.0 × 10⁷ km |
|---|---|
| Mass | 2.27 × 10³¹ kg |
| Diameter compared with Earth | 816 × Earth |
| Distance | 250 light-years |
| Orbit | 4 days |
| Brightness | About 20,000 Suns |
Good to know
- Hipparchus used it to discover the slow wobble of Earth's axis, around 130 BC.
- The larger star may one day explode as a supernova.
- It is one of the 20 brightest stars in the night sky.