Sharing the Light of Two Suns

This artist's concept illustrates Kepler-47, the first transiting circumbinary system -- multiple planets orbiting two suns – 4,900 light-years from Earth, in the constellation Cygnus. The system was detected by NASA's Kepler space telescope, which measures minisucule changes in the brightness of more than 150,000 stars to search for planets that pass in front of or 'transit' their host star.As seen from our vantage point on Earth, the two orbiting stars regularly eclipse each other every 7.5 days. One star is similar to the sun in size, but only 84 percent as bright. The second star is diminutive, measuring only one-third the size of the sun and less than one percent as bright.