Six small planets orbiting a sun-like star amaze astronomers

Six small planets orbiting a sun-like star amaze astronomers

(PhysOrg.com) -- A remarkable planetary system discovered by NASA's Kepler mission has six planets around a Sun-like star, including five small planets in tightly packed orbits. Astronomers at the University of California, Santa Cruz, and their coauthors analyzed the orbital dynamics of the system, determined the sizes and masses of the planets, and figured out their likely compositions--all based on Kepler's measurements of the changing brightness of the host star (called Kepler-11) as the planets passed in front of it.