Two Swiss scientists say they have discovered the first planet outside Earth’s solar system, revolving around a star in the constellation Pegasus.
In the past, planet-like material had been found only around dead, collapsed stars, and it was not clear whether they were planets or leftovers from the star’s demise. If verified, the unnamed planet would be the first found in a “live” solar system.
The astronomers, Michel Mayor and Didier Queloz, made the claim at a conference entitled “Cool Stars, Stellar Systems and the Sun,” held Friday in Florence to discuss the possible existence of planets revolving around other suns, and maybe even one like Earth that harbors life.
The Swiss astronomers said the planet revolves around a star named 51 Pegasus, which is visible from Earth. The planet cannot be seen by high-powered telescopes because it is all but swallowed up in the intense light of 51 Pegasus. But the nearby planet makes light from the star oscillate, a sign that it is being pulled by something nearby, the Swiss pair reasoned.
Using mathematical calculations, they concluded that it is a planet about the size of Jupiter, largely made up of hot gases. In no way could it support life, said the scientists, who work at the Geneva Observatory. The body revolves around 51 Pegasus once every four Earth days, they said, suggesting it is very close to the star. Mayor and Queloz observed 51 Pegasus from a telescope in southern France.
The announcement was greeted by heavy applause and some doubt, Italian newspapers reported. “How long could a planet last so close to the principal star without evaporating from the effect of the enormous quantity of energy it absorbed?” asked Franco Pacini, director of Italy’s Arcitre observatory. The findings are being checked by Nature magazine, a British publication, newspaper reports said.
“Still,” Pacini said, “this is the first suspected finding of a planet revolving around a sun somewhat like ours.”
The star 51 Pegasus is similar to the sun in temperature, but about 8 billion years old, about 3 billion years older than the sun.