Mass of Closest White Dwarf Measured |
|
Written by spacetravel.org
|
|
Saturday, 17 December 2005 20:00 |
|
An international team of astronomers using the Hubble Space Telescope have accurately measured the mass of Sirius B, the nearest white dwarf star to Earth.
Until recently, it has been hard to study Sirius B, which was discovered in 1862, because of the bright light emitted by its neighbour, Sirius A, also known as the Dog Star. The team was able to use Hubble's imaging spectrograph to analyse light from Sirius B. They based their calculations of the dwarf stars mass on how its light is distorted by Sirius As intense gravitational field.
Sirius B is only 12,000 kilometres in diameter, similar to Earth, but its mass is about 98 percent that of the sun, and its gravitational field is about 350,000 times greater than the Earth's.
|