Fastest-rotating star spins at 600 km per second!
Washington: Scientists have for the first time discovered the fastest-rotating massive star, which spins at the speed of 600 kilometers per second at the equator and could be the progenitor of some of the brightest explosions in the universe: gamma-ray bursts.
The rotational velocity is so high that the star is nearly tearing apart due to centrifugal forces.
The observations were made at the European Southern Observatory’s Very Large Telescope, at the Paranal Observatory in Chile, as part of a survey of the heaviest and brightest stars in a region called the Tarantula Nebula.
The Tarantula Nebula is a region of star formation located in a neighbouring galaxy called the Large Magellanic Cloud, about 160,000 light years from Earth.
The reported star, VFTS 102, is extremely hot and luminous, shining about 100,000 times more brightly than the sun. According to the research team, this star had a violent past and was ejected from a double star system by its exploding companion star.
Matteo Cantiello and collaborators explained that stars could reach such rapid rotation via a ‘cosmic dance’ with another star so close that gravity strips gas from its surface.
“This gas falls onto the companion star, increasing the mass and spinning it up,” said Cantiello.
“Similar to a tennis ball spinning fast after being hit by a glancing blow, a star rotates quickly after being hit off-center by the in-falling gas.”
The star is unusual not only because it rotates so fast, but also because it is moving away from its neighbouring stars at a velocity of about 70,000 miles per hour, or 30 kilometers per second.
“Having been part of a binary system could explain this space oddity,” said Cantiello.
The star is located close to a pulsar and a supernova remnant, which may be left over from the companion star that once spun-up the observed star.
Cantiello said that this star might produce dramatic fireworks as it dies.
The study has been recently published in the Astrophysical Journal Letters.