Free Astronomy Magazine November-December 2016

18 SPACE CHRONICLES by NASA A distant planet orbiting two stars, found by its warp- ing of spacetime, has been confirmed using ob- servations from the NA- SA/ESA Hubble Space Telescope. The planet’s mass caused what is known as a microlens- ing event, where light is bent by an object’s gravita- tional field. The event was ob- served in 2007, making this the first circumbinary planet to be con- firmed following detection of a mi- crolensing event. Microlensing is the weakest form of gravitational lensing — the bend- ing of the path of a light ray by some body of mass between a light source and an observer. While strong lensing can lead to multiple images of the same object or to distorted arcs, microlensing causes a change in the brightness of the distant object. The majority of exoplanets detected so far orbit single stars. Only a few Hubble helps find light world with two suns NOVEMBER-DECEMBER 2016