55 Cancri ( /ˈkæŋkraɪ/ or /ˈkæŋkriː/), also cataloged Rho1 Cancri or abbreviated 55 Cnc, is a binary star approximately 41 light-years away from Earth in the constellation of Cancer. The system consists of a G-type star and a smaller red dwarf, separated by over 1,000 AU (one thousand times the distance from the Earth to the Sun).
As of 2011, five extrasolar planets have been confirmed to be orbiting the primary, 55 Cancri A (the yellow dwarf). The 55 Cancri system was the first known to have four, and later five planets, and may possibly have more. The innermost planet, e, transits 55 Cancri A as viewed from Earth. The next planet, b, is close enough to edge-on that its upper atmosphere transits the star.
Read more about 55 Cancri: Distance and Visibility, System Components, Planetary System, Communication