Science / Medicine : New Group of Fast Pulsars Found

A multinational team of astronomers has found an unprecedented collection of stars that emit very fast bursts of energy--a discovery that may help in studying the formation of galaxies. The researchers reported last week in the journal Nature that they found 10 “millisecond pulsars� in a single cluster of other stars, almost doubling the known number of the objects.

Pulsars are dense stars that appear to emit energy in very regularly spaced bursts. In fact, they are thought to send out the energy in a constant beam that sweeps across the sky as the star rotates, like light from a lighthouse. An earthbound observer detects a burst every time a beam crosses Earth. Millisecond pulsars appear to “blink� at intervals measured in thousandths of a second.

The 10 new millisecond pulsars, which emit radio waves, were found in a star cluster called 47 Tucanae. Finding so many in one area will help scientists study the history of star clusters, called globular clusters, said astrophysicist David Helfand of Columbia University in New York. Globular clusters may have played a key role in galaxy formation, so studying them could shed light on that process, he said.