51 Pegasi system
From Halopedia, the Halo wiki
Template:SeeWikipedia 51 Pegasi is a system approximately 50.1 lightyears away from Earth, in the constellation Pegasus.[1] The stars planetary system was controlled by the Covenant during 2545[2], and was home to 51 Pegasi B and Pegasi Delta, used by the Covenant in mining deuterium and tritium in the planetoids rich oceans.
51 Pegasi was the very first main sequence (sun-like) star discovered to have a planet in orbit around it.