You spin me white round

The European Space Agency’s XMM-Newton X-ray telescope has uncovered the fastest rotating white dwarf ever observed in the Universe.

The white dwarf, in its final stages of life as a star, is emitting X-rays, which were first spotted in 1997. Now, thanks to the XMM-Newton’s sensitivity, astronomers have found the object to be no ordinary white dwarf.

Normally white dwarfs squeeze just over half the mass of the Sun into an object the size of Earth. This particular white dwarf contains at least double that mass but has a diameter just half that of Earth. It is almost ready to go supernova and rotates once every 13 seconds, the fastest revolution rate ever observed.

When the star becomes too unstable it will either collapse into an even more compact object called a neutron star or it will explode into a type la supernovae. These supernovae are used by astronomers as standard beacons to measure cosmic distances and eventually understand the expansion of the Universe. This is the first time that astronomers have found an accreting white draft in a binary system where the mass could also be determined accurately.

Although the star is in our cosmic neighbourhood and likely to explode in a few million years’ time it is not close enough to pose a threat to Earth. However, our descendants are in for an astronomical treat - when the star goes supernova it will be a spectacular celestial sight. Astronomers predict that it will light up the sky with the intensity of the full moon and be so bright it can be seen during the day with the naked eye.

By Leila Sattary