This diagram illustrates the locations of the star systems closest to the sun. The year when the distance to each system was determined is listed after the system's name.
NASA's Wide-field Infrared Survey Explorer, or WISE, found two of the four closest systems: the binary brown dwarf WISE 1049-5319 and the brown dwarf WISE J085510.83-071442.5. NASA's Spitzer Space Telescope helped pin down the location of the latter object.
The closest system to the sun is a trio of stars that consists of Alpha Centauri, a close companion to it and the more distant companion Proxima Centauri.
For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer.
More information for WISE is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise.