Planets Orbiting Other Suns

ABSTRACT After a century fraught with false claims, evidence for planets around other stars finally appears robust. Infrared imaging and spectroscopy of disks around stars foreshadow detailed models of the formation and evolution of planetary systems. Surveys of main‐sequence stars show that 5% harbor companions of (0.5–8)MJUP within 3 AU, peaked at lowest masses. Their orbits are either within 0.2 AU or eccentric, and occasionally both. These odd orbits suggest that dynamics with gas and planetesimals yield diverse systems and that stable, coplanar orbits of about nine giant and rocky planets may require special initial conditions. Far fewer stars (<1%) harbor (5–80)MJUP companions. This brown dwarf desert for companions stands in contrast to the abundant brown dwarfs that are freely floating.

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