An international team of astronomers including Alex de Koter and Hugues Sana from the University of Amsterdam (UvA) has discovered a super-fast spinning star in the Large Magellanic Cloud.
An international team of astronomers including Alex de Koter and Hugues Sana from the University of Amsterdam (UvA) has discovered a super-fast spinning star in the Large Magellanic Cloud. The equatorial rotation speed (the speed at which the star is spinning) of the star VFTS 102 is estimated at more than two million kilometres per hour, making it the fastest-spinning star ever recorded by astronomers. The results of their observations have been published in Astrophysical Journal Letters.
At a distance of 160,000 light years, the Large Magellanic Cloud galaxy is a relatively near neighbour of our own Milky Way. The astronomers made their discovery with the ESO’s Very Large Telescope in Chile, which is being used to map the most massive and brightest stars in the Large Magellanic Cloud’s Tarantula Nebula. In fact, the team found a number of remarkably fast-rotating objects. According to co-author Hugues Sana, ‘The Tarantula Nebula is like an enormous incubator for stars and is the perfect place to find these kinds of unusual objects’.
VFTS 102 is rotating on its axis at three hundred times the speed of the sun, approaching the point at which centrifugal forces would tear the star apart. Based on the fact that it is moving through space much faster than the surrounding stars, VFTS 102 is presumed to be a ‘runaway star’. The astronomers think it was probably hurled out of a binary star system when its companion star exploded in a supernova. A gas cloud typical of that left by a supernova in the vicinity of VFTS 102 supports this theory. In this scenario, the distance separating the two stars was relatively small, resulting in gas from the companion flowing towards the primary star and making it, in turn, spin ever faster. During the supernova, the core of the companion star collapsed to leave a pulsar.
‘What fate has in store for this massive, fast-rotating star is unclear’, says De Koter. ‘The immense speed at which VTFS 102 is turning is causing its internal layers to mix into a completely homogenous composition. It’s possible’, he conjectures, ‘that a star like this will end its days in some exotic form of supernova explosion, such as a gamma-ray burst or hypernova’.
P.L. Dufton, P.R. Dunstall, C.J. Evans, I. Brott, M. Cantiello, A. de Koter, S.E. de Mink, M. Fraser, V. H’enault-Brunet, I.D. Howarth, N. Langer, D.J. Lennon, N. Markova, H. Sana, W.D. Taylor: The VLT-FLAMES Tarantula Survey: The fastest rotating O-type star and shortest period LMC pulsar – remnants of a supernova disrupted binary? Astrophysical Journal Letters (vol. 743, nr. 1).