The cast of exoplanets has an extraordinary new member. Using ESO’s telescopes, astronomers have discovered an approximately seven- Jupiter-mass companion to an object that is itself only twice as ...

Double vision, or diplopia, occurs when a person sees two images instead of one. Performing certain eye exercises may help to reduce double vision in some cases. When a person has double vision, the ...

Known since the earliest days of naked-eye astronomy, the Double Cluster in Perseus appears in the star catalog of Greek astronomer Hipparchus in 130 B.C. The two clusters are now designated h and Chi ...