Researchers look for gravity waves from pulsars

17 Jun 2002

Can pulsating stars emit gravitational waves detectable on Earth? Researchers Nils Andersson of Washington University (nils@howdy.wustl.edu) and Kostas Kokkotas of the Aristotle University of Thessaloniki (Greece) report on the likelihood of measuring gravitational waves coming from single stars, such as pulsating neutron stars created in a supernova. Until recently theorists have largely concentrated on the hypothetical disturbances caused by binary systems, such as pairs of black holes or neutron stars.

The calculations, reported in the AIP Physical Review of Letters, take into account details of general relativity overlooked in many previous studies. For example, the gravitational bang from Supernova 1987A could have been seen by present-day detectors if as little as one millionth of a solar mass of the supernova's energy had been dispatched in the form of gravitational waves, the researchers argue. If this fraction were as high as several percent, neutron stars formed in supernovas as far away as the Virgo Cluster could be detected gravitationally at a rate of several per year.

The authors also contend the gravitational wave signal can be decoded to provide detailed information about the star. Gravitational wave monitors are essentially elaborate strain gauges employing suspended masses or interferometers that signal the appearance of faint, passing distortions in space. In assessing the chances of observing such a wave.