51 Pegasi B
From Halopedia, the Halo wiki
The Covenant constructed a massive refinery on the planet's moon, Pegasi Delta. Serving as a supply station, the system was to be a Covenant forward staging post for incursions into UNSC space, as Covenant ships would come here and refuel, resupply, and gather to attack the enemy. In 2545, the Spartan-III Beta Company was sent on an attack on this facility during Operation: TORPEDO. Though they successfully destroyed the facility, 298 of the Spartans were killed in the battle, leaving only Lucy-B091 and Tom-B292 alive.
The planet 55 Pegasi b and the star 51 Pegasi exist in real life, within the constellation Pegasus, 50.1 light years from Earth. 51 Pegasi b was the first ever planet discovered orbiting a sun-like star.
List of appearances