With the discovery last month of three more planets orbiting nearby stars, the number of proposed extrasolar planets now totals more than 50. The three objects were found with a high-precision spectrograph that analyzes starlight beaming into the 4-meter Anglo-Australian Telescope near Coonabarabran, Australia. Researchers have used the telescope since 1998 to search for planets among 200 nearby stars in the southern sky.
The lightest of the three planets is at least 84 percent as massive as Jupiter and lies within roasting distance of its parent star, orbiting at about one-tenth the distance that Mercury circles the sun. That new find whips around its star in a mere 3 days.
The heaviest of the bodies, an object with a minimum mass nearly twice that of Jupiter, has an elliptical orbit and takes just over 2 Earth years to orbit its parent star, mu Ara, in the constellation Altar. The planet's average distance from its parent is just slightly greater than Mars' average di