Artist's impression of the sizes of Sirius B and the Earth
![](https://cdn.sci.esa.int/documents/34247/35306/1567213718870-heic0516c_625.jpg)
Date: 12 December 2005
Satellite: Hubble Space Telescope
Depicts: Sirius B
Copyright: ESA and NASA
Based on the Hubble measurements made with the Space Telescope Imaging Spectrograph, an international team found that Sirius B has a mass that is 98 percent that of our own Sun. Despite this large mass Sirius B is only 12 000 kilometres in diameter, making it smaller than even the Earth and much denser. Sirius B's powerful gravitational field is 350 000 times greater than Earth's, meaning that a 68 kilogram person would weigh 25 million kilograms standing on its surface.
Last Update: 1 September 2019