Posted: Fri, Jun 14, 2002, 8:19 AM ET (1219 GMT)
Astronomers announced Thursday the discovery of 15 new extrasolar planets, including one that is the closest analogue to Jupiter yet found. A team of astronomers led by veteran planet discoverers Geoffrey Marcy and Paul Butler said Thursday that one of the 15 new planets they found, 55 Cancri d, is four times the mass of Jupiter and has an orbit very similar to Jupiter's. The planet is part of a solar system of at least three planets; the other two, including one whose discovery was also announced Thursday, orbit close to the parent star. Theoretical studies show that terrestrial planets could exist in stable orbits between the inner and outer gas giants, but such planets are entirely speculative at this time as current planet discovery techniques cannot detect them. Astronomers also found the smallest exoplanet to date, a planet with a mass just 12 percent that of Jupiter. The discoveries bring the total number of exoplanets around Sunlike stars to over 90; the first was discovered less than eight years ago.
