Star system

A star system, or solar system, was a group of objects, usually planets, orbiting a star or stars.

Star systems
The First Doctor's granddaughter Susan Foreman learned about Earth and its solar system in her spatial cartography lessons. (AUDIO: The Beginning)

There were eleven planets in the Rhumos system until the arrival of Vortis. (PROSE: Twilight of the Gods)

The Beacon/Ember system contained the planet Caresh. A passing neutron star threatened to disrupt the planet's orbit, but Lord Roche and the Third Doctor moved it into a closer stable orbit around Ember. (PROSE: The Suns of Caresh)

Tigella and Zolfa-Thura were in the Prion system. (TV: Meglos)

The Unukalhai system was used by the Tzun Confederacy. However, they were gone by 2247 when the sixth moon of Unukalhai IV was terraformed for human colonisation. (PROSE: Lords of the Storm)

Thoros Alpha and Beta were in the Thoros system. (TV: Mindwarp)

The binary Althosian system had seven planets. They were all destroyed in 2400 to prevent an Yssgaroth invasion. (PROSE: The Pit)

There were twenty-three planets in the Bel system. (PROSE: Beltempest)

The New Washington System was at the edge of the Mutter's Spiral, 18.9 light years away from Justicia. It had twelve planets, four of which were inhabited. The Blathereen planned to destroy the planets in the system in 2501 to test the destructive capabilities of Justicia, but they were stopped before they could carry out their plans. (PROSE: The Monsters Inside)

The Scarlet System was home to the Pallushi, a mighty civilisation that spanned a billion years. It was destroyed when it fell into a black hole in 43K2.1. (TV: The Impossible Planet)

Raxacoricofallapatorius and its twin planet Clom were in a star system was located in the Isop Galaxy. (TV: Love & Monsters, TV: SJAF 4)

The Calypso V system had ten planets, including New Venus, Ur XVII and Venice. (PROSE: The Coming of the Terraphiles)

The Tiberian spiral galaxy contained a million star systems when it was destroyed at the end of the Great Cyber War. (TV: Nightmare in Silver)

One of the first human colonies settled after Earth's population had been evacuated was located in a binary system. (TV: Smile)

Fate
Emerging from the pocket universe after surviving the Last Great Time War, Gallifrey was situated at the end of the universe, "give or take a star system". (TV: Hell Bent)

Other references
On Trenzalore, Vastra scanned for local star systems, finding that they were disappearing as a result of the Great Intelligence's attack on the Eleventh Doctor's time stream. (TV: The Name of the Doctor)