Planet waves

no more controversies. It looks like there really is a planet orbiting the star 51 Pegasi. This new development has discredited all previous theories suggesting that the planet was merely a mirage.

Three years ago, Michel Mayor and Didier Queloz of the Geneva Observatory reported that the star 51 Pegasi was wobbling from the gravitational pull of an orbiting planet. It was the first planet ever found around another Sun-like star.

Earlier in 1997, however, David Gray of the University of Western Ontario in Canada, asserted that 51 Pegasi's planet did not exist. The star was pulsating, which caused the periodic change in its spectrum that planet hunters had "mistaken" for a planet, he claimed. Other astronomers have now searched for the alleged pulsation but with no success.

One team used a telescope at Mount Hopkins in Arizona to obtain high-quality spectra of 51 Pegasi.If the star were pulsating, the shapes of the spectral lines should vary. But they remained constant. The results have been confirmed by other teams. The planet's discoverers have welcomed the news. "We are very glad," Mayor has reportedly said (New Scientist , Vol 156, No 2112).