Stellar remnants · White dwarf
Sirius B
8.6 light-years · Light crosses it in 0.039 seconds
- Across
- 11,688 km
- Vs Earth
- 0.92× Earth
- Mass
- 1.02 Suns
About
Sirius B is the burnt-out core of a star that was once more massive than Sirius itself. It has about the mass of the Sun packed into a body the size of Earth, and it no longer produces energy — it is simply cooling, and will keep cooling for billions of years.
About the size of Earth but as massive as the Sun.
At a glance
| Mass | 1.02 Suns |
|---|---|
| Size | Slightly smaller than Earth |
| Surface | About 25,000 °C |
| Found | 1862 |
Did you know
- Its existence was predicted in 1844 from a wobble in Sirius's motion, 18 years before anyone saw it.
- One teaspoon of it would weigh about five tonnes.
- It is 10,000 times fainter than Sirius A, which is why it is so hard to see beside it.
Simulations
- The Sun's death — How the Sun will swell into a red giant, then fade into a white dwarf
Real photo
- Sirius A with its tiny white-dwarf companion Sirius B beside it, Hubble — NASA, ESA, H. Bond (STScI), and M. Barstow (University of Leicester) (CC BY 4.0) · source