Planet hunters this week announced they had found two planetary systems, one of which resides only 15 light-years from Earth. Each system features a star roughly similar to the sun and a bizarre entourage that defies ready explanation and may provide fresh insight into planet formation.
Among the 50 or so stars where extrasolar planets have been detected, astronomers have reported only one with more than a single planet (SN: 4/17/99, p. 244). The new finds harbor several surprises. One system features an orbiting body so massive it may qualify as a failed star. The other system features two planets with an unusual orbital harmony.
A team led by Geoffrey W. Marcy of the University of California, Berkeley and R. Paul Butler of the Carnegie Instituti