First gamma-ray-only pulsar is discovered

WASHINGTON, Oct. 16 (UPI) -- The U.S. space agency says its Fermi Gamma-ray Space Telescope has discovered the first gamma-ray-only pulsar.

The National Aeronautics and Space Administration said the10,000-year-old stellar corpse sweeps a beam of gamma-rays toward Earth about three times a second.

"This is the first example of a new class of pulsars that will give us fundamental insights into how these collapsed stars work," said Stanford University's Peter Michelson, principal investigator for the Fermi telescope.

NASA said the gamma-ray-only pulsar lies within a supernova remnant known as CTA 1, about 4,600 light-years away from Earth in the constellation Cepheus.

"A pulsar is a rapidly spinning neutron star, the crushed core left behind when a massive sun explodes," the space agency said. "Astronomers have cataloged nearly 1,800 pulsars. Although most were found through their pulses at radio wavelengths, some also beam energy in other forms, including visible light and X-rays. However, CTA 1 only pulses at gamma-ray energies."

The Fermi Gamma-ray Space Telescope was formerly known as the Gamma-ray Large Area Space Telescope, or GLAST.

A paper about the new pulsar appears in the online journal Science Express in advance of print publication.