The sun rotates at a respectable 2 kilometers per second, which may sound pretty fast. But according to a study to be published in The Astrophysical Journal Letters (arXiv:1111.0157v1), a star has been detected in 30 Doradus (a.k.a. the Tarantula Nebula in the Large Magellanic Cloud, 160,000 light-years away) spinning at the breakneck speed of 600 kilometers per second!
According to Ken Croswell at ScienceMag.org, if the star spun just 20 percent faster, centrifugal forces would rip the star to shreds. If an aircraft could travel this fast, it could fly from New York to Los Angeles in a little under 7 seconds!
We often hear of rapidly spinning compact objects, like pulsars — spinning, X-ray-emitting neutron stars — but rapidly spinning normal stars are very rare. In the case of VFTS 102, it's a real oddity and it's a record-breaker.
The young, blue, O-type star must have been sped up in some way. After all, stars spinning this fast aren't born naturally.
The international team of astronomers working on this study think they know why VFTS 102 is in such a mess. When looking around the star's neighborhood, they noted a pulsar speeding away from VFTS 102, as if running from the scene of a crime. They believe the pulsar may also be the victim of the event that caused VFTS 102's strange spin.
Once a binary pair — two stars mutually orbiting each other — one of the stars exploded as a supernova. As the supernova detonated, leaving the pulsar behind as a supernova remnant, the ejected gas was dumped onto VFTS 102. The rapid increase in mass caused the star to be "spun up."
As mass was lost in an instant from one of the stars as it exploded, the gravitational bond between the stars was lost, causing the pair to be flung away from each other, much like a hammer-thrower releasing a hammer. This is why both the pulsar and VFTS 102 are flying apart.
The researchers believe that the future for VFTS 102 is grim. After sucking in a huge quantity of material from its sibling's supernova, it now weighs in at 25 times the mass of our sun. Therefore, VFTS 102 will likely end its life in the largest explosion known: a gamma-ray burst.
As it's so massive, this huge explosion will leave a black hole in its wake.
Image: Hubble observation of 30 Doradus. (Morgan Fraser/Philip Dufton/Paul Dunstall/Hubble Legacy Archive).