Cosmic Scale
Eta Carinae
Luminous blue variable · 7,500 light-years
How big is Eta Carinae?
Eta Carinae is about 3.3 × 10⁸ km across.
See Eta Carinae in 3D, at true scale
Eta Carinae is one of the most massive and luminous stars in our galaxy, about 5 million times brighter than the Sun. In 1843 it erupted and briefly became the second-brightest star in the sky, throwing off the Homunculus Nebula. Its size is uncertain: estimates range from 60 to over 800 Suns across, and the value shown here is a middle one.
At a glance
| Diameter | 3.3 × 10⁸ km |
|---|---|
| Mass | 1.99 × 10³² kg |
| Diameter compared with Earth | 26,200 × Earth |
| Distance | 7,500 light-years |
| Brightness | About 5 million Suns |
| Great Eruption | 1843 |
Good to know
- It is really two stars; the smaller one orbits every 5.5 years.
- It is expected to explode as a supernova, perhaps within the next hundred thousand years.
- It lives inside the Carina Nebula.
- Next smaller: Deneb · 2.8 × 10⁸ km
- Next larger: Pistol Star · 4.3 × 10⁸ km