- You may be looking for Kasterberous system.
Kasterborous (Cas-TER-bor-os), (TV: Pyramids of Mars) or the Kasterberous system, (PROSE: Prisoners of the Sun) was the constellation, (TV: Pyramids of Mars) or "star system", (PROSE: Prisoners of the Sun) in which the planet Gallifrey (TV: Pyramids of Mars) and the Kasterboron Borealis were located. (AUDIO: Neverland)
The Sixth Doctor mentioned that Kasterborous was made up of seventeen suns. (AUDIO: Trial of the Valeyard) When explaining where they were from, the Doctor sometimes mentioned that Gallifrey was located in Kasterborous, (TV: Attack of the Cybermen, Voyage of the Damned, The Day of the Doctor, Spyfall; AUDIO: An Earthly Child) as did Jack Harkness and Clara Oswald while pretending to be the Doctor. (AUDIO: Piece of Mind, TV: Death in Heaven)
According to another account, the name originated from Kasterborus, an astrologer who gave the largest contribution to "neo-astrology", occurring between the third millennium and the beginning of the fourth millennium. This led the inhabitants of Gallifrey naming the constellation after Kasterborus, in a rare display of humour. (PROSE: Introduction and links)
During the War in Heaven, Kasterborous was torn apart and erased from history when the Eighth Doctor used the Edifice to destroy Romana III's Gallifrey. In the post-War universe, Marnal was unable to find Kasterborous anywhere in space or time. (PROSE: The Gallifrey Chronicles)