Nearby Neighbor Joins Extrasolar Planets Roster
(From the September/October 1998 issue of StarDate magazine)
Planet hunters have discovered the nearest world to our own solar system orbiting a faint, red star in the constellation Aquarius.
Two teams of astronomers detected a giant planet, about 1.6 times the mass of Jupiter, orbiting the star Gliese 876, which is 15 light-years from Earth. The star is only about one-third as massive as the Sun, and its surface is cooler and redder than the Sun's. The planet orbits Gliese 876 once evey 61 days at about one-fifth the distance from Earth to the Sun.
One of the teams that made the discovery, headed by Geoffrey Marcy and Paul Butler, also reported that planets appear to orbit 14 of 350 Sun-like stars studied over the last three years. The discoveries bring the total number of possible planetary systems to more than two dozen.
Astronomers discovered all of these planets by measuring slight fluctuations in the wavelengths of light from the parent stars. Astronomers say the fluctuations are caused by the gravitational tug of unseen planets. -- — Damond Benningfield
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