Kasterborous
The Constellation of Kasterborous (Cas-TER-bor-os), (TV: Pyramids of Mars) also spelled Casterbrious (PROSE: Time is Everything) was the constellation of the planet Gallifrey. (TV: Pyramids of Mars) One account indicated Gallifrey was located in the Kasterberous system, indicating that references to Kasterborous may have referred to Gallifrey's star system rather than a constellation. (PROSE: Prisoners of the Sun)
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 others pretending to be the Doctor, such as Jack Harkness (AUDIO: Piece of Mind) and Clara Oswald. (TV: Death in Heaven)
Features
The Sixth Doctor mentioned that Kasterborous was made up of seventeen suns. (AUDIO: Trial of the Valeyard)
Kasterborous was "just to the left of Karn". (AUDIO: Vortex Ice) Other celestial bodies near Gallifrey included Reave, (AUDIO: A Heart on Both Sides) the gas giant Polarfrey, the asteroid Kasterborous the Fibster, (PROSE: Lungbarrow) and Gallifrey's moon, Pazithi Gallifreya. (PROSE: Cat's Cradle: Time's Crucible)
Ardethe, one of the Nine Homeworlds, (PROSE: The Story So Far...) lay in the constellation of Kasterborous, (PROSE: Deadfall) as did the Kasterboron Borealis star cluster. (AUDIO: Neverland)
Space Station Zenobia hid near a red supergiant star in a lifeless region of space at the edge of Kasterborous. (PROSE: The Infinity Doctors) New Peerlessness was built by the Time Lords near Kasterborous. (AUDIO: Persuasion)
History
According to Ruath, the Minyans referred to the region of space as a constellation. (PROSE: Goth Opera)
Another account stated; 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)
The Doctor's parents owned a summer house in Kasterborous. (PROSE: The Infinity Doctors)
The Racnoss Wars were waged by the Time Lords in response to a precognition foreseeing Racnoss Webstars swarming throughout Kasterborous. (AUDIO: Empire of the Racnoss)
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)
As no Time Lord was allowed to know Gallifrey's personal future, TARDISes were prevented from entering Kasterborous after a certain date. (PROSE: Goth Opera)
During the early days of the Last Great Time War, the Eighth Doctor returned Susan Foreman to Kasterborous, his granddaughter returning to Gallifrey via teleport. (AUDIO: The Shoreditch Intervention) Much later, the Daleks launched a successful incursion into Kasterborous (PROSE: Dalek) and then invaded Gallifrey itself. (TV: The Day of the Doctor, PROSE: The Day of the Doctor)
At the end of history, Pallant theorised that the Needle People were descended from the half-human half-Time Lord "Children of Kasterborous". (PROSE: The Infinity Doctors)