Feb. 21, 2007 — What might be the fastest top in the universe has been spotted spinning far quicker than astronomers thought possible.
The six-mile-wide, unimaginably dense neutron star might be whirling and flashing out X-rays at 1,122 rotations per second, which is far quicker than the 619 rotations per second (Hz) of the next fastest neutron star and well above 760 Hz, which astronomers thought was the cosmic speed limit for neutron stars.
The high speed of the star, XTE J1739-285, if confirmed, could reveal a lot of very weird things going on inside neutron stars.
"The faster the star rotates the more interesting it gets," says neutron star researcher Fridolin Weber at San Diego State University. "This by far the fastest."
Like a spinning ice skater who can spin faster by holding in her arms, neutron stars can only spin faster if they are very small and very dense. To attain such super densities, the very protons and neutrons in the nuclei of the atoms that make up the star need to pack like sardines.
But that’s nothing compared to what would be required to get a star spinning faster than 700 Hz, said Weber.
"At 700 Hz it puts some limits on the equation of state," said Weber, referring to the limits of how closely you can pack atomic nuclei to get enough matter — and therefore enough gravity — to hold the star from flying apart.
Above 700 Hz strange things start being required of matter inside the star, Weber explained to Discovery News. Protons and neutrons start overlapping and strange new particles begin appearing — like hyperons and bosons — that allow the density to exceed ten times that of a typical atomic nucleus. Likewise, they allow the star to shrink.
"(High speed) would favor these exotic states of matter," said Weber.
