Cosmic Scale
Pollux
Orange giant · 34 light-years
How big is Pollux?
Pollux is about 1.3 × 10⁷ km across.
See Pollux in 3D, at true scale
Pollux is the brightest star in Gemini and the closest giant star to the Sun. It has finished burning hydrogen in its core and swollen to nine times the Sun's width — a preview of the Sun's own future.
At a glance
| Diameter | 1.3 × 10⁷ km |
|---|---|
| Mass | 3.80 × 10³⁰ kg |
| Diameter compared with Earth | 989 × Earth |
| Distance | 34 light-years |
| Surface | 4,586 K |
| Brightness | 43 Suns |
| Planet | Pollux b, confirmed 2006 |
Good to know
- Its planet is more than twice Jupiter's mass and takes 590 days to orbit.
- Despite the twin story, Pollux and Castor are not related: they lie at different distances and are different kinds of star.
- It is one of the few giant stars close enough to study in fine detail.
- Next smaller: Spica · 1.0 × 10⁷ km
- Next larger: Sagittarius A* · 2.5 × 10⁷ km