The Fastest-Spinning White Dwarf Ever Observed Rotates Once Every 25 Seconds

Thanks to gas siphoned from a nearby red dwarf star.

Chris Young
The Fastest-Spinning White Dwarf Ever Observed Rotates Once Every 25 Seconds
An artist's impression of a white dwarf.ESO/M. Kornmesser

If we were somehow able to land on a newly-discovered white dwarf star without being burnt to a crip, a whole day would last as little as 25 seconds.

That’s because scientists from the University of Warwick, UK just observed the fastest-spinning white dwarf to date, making one rotation every 25 seconds. The dwarf star, called LAMOST J0240+1952, beat the previous record-holder by five seconds, a report in ScienceNews reveals.

Spinning right round

For reference, the sun and moon both rotate approximately once an Earth month. LAMOST J0240+1952, on the other hand, rotates more than twice a minute. This makes it the fastest star of any kind to have ever been observed by the scientific community — not counting neutron stars, which are the collapsed cores of massive supergiant stars.

The discovery was made by University of Warwick astronomer Ingrid Pelisoli and colleagues after they noticed a burst of light from the white dwarf star, which is closely neighbored by a red dwarf star. They realized that this short light burst occurred once every 24.93 seconds, revealing the white dwarf star’s rotation period. Typically, a white dwarf will take hours or days to spin. However, the newly-discovered star, which is located in the Aries constellation, moves so quickly because of the nearby red dwarf star which is feeding gas into LAMOST J0240+1952, making it rotate incredibly quickly. Pelisoli and her team published their findings in a paper available on preprint server arXiv. 

White dwarf stars reveal mysteries of the universe

White dwarf stars are some of the oldest observable celestial objects in the universe and they have been at the center of several dramatic scientific observations in recent years. Last year, for example, astronomers turned to neutron stars and white dwarf stars to help them prove Einstein’s theory of relativity via the observation of frame-dragging, whereby spacetime is altered by massive rotating objects. 

White dwarf stars eventually crystallize into metallic oxygen and carbon. Source: The University of Warwick

University of Warwick astronomers have also previously revealed direct observations proving that thousands of white dwarf stars in our galaxy have gradually crystallized as they cooled down over millennia, and that our own sun will one day meet the same fate — though it likely won’t rotate every 25 seconds before it eventually cools down into a crystal core of metallic oxygen and carbon. This discovery means that some white dwarf stars are billions of years older than had been previously estimated. The oldest of all might be roughly the same age as the universe itself, meaning that uncovering the mysteries of white dwarf stars promises to teach us a great deal about the history of the cosmos.