The Khi system

Khi
Khi is a red giant in the Middle Tenebrarum arm. Khi was once a G type yellow dwarf like the sun but over time it expanded and engulfed 1 of its planets and boiled away the oceans of another. But even in this destruction life still emerged on another planet in the system.

Khi I
Khi I is the currently the closest planet to Khi. Because of this it is evaporating very slowly and is covered in oceans of lava. Khi I will be completely gone in 4 billion years when it finally evaporates away.

Khi II
Khi II was once habitable until about 3 billion years ago when Khi expanded the oceans boiled away. Khi II was home to a civilisation that was equivalent to Humans in the early 21st century. Some of the probes they launched are still around flying through galactic space. One of the rovers they launched to explore Khi III wasn't sterilized properly and some bacteria laid dormant on the rover until Khi expanded.

Khi III
Khi III is a small planet that was once uninhabitable but ever since Khi expanded most of the ice melted making oceans. many rovers were sent here by the extinct civilisation to explore the planet and were supposed to be sterilized to prevent contamination. When the ice melted and oceans formed one of the rovers was submerged and the bacteria that was on it woke up. Around 2 billion years ago multi cellular life emerged in the form of plant like organisms at the bottom of the ocean filtering microbes with leaf like appendages. No intelligent creatures have evolved yet on Khi III.

Khi IV
Khi IV is the largest planet in the Khi system. Khi IV is a gas giant approximately the size of Jupiter. Khi IV has a large ring system and about 70+ moons. Most of the moons are very small with about 6 major moons and 9 minor ones making up the largest of them. Khi IV is a bluish green colour with a hexagonal storm on both poles.

Khi V
Khi V is a large super earth covered in ice. The ice is a strange dark red colour from dust particles frozen inside it. there were approximately 4 probes sent to Khi V but no landers. One of the orbiters still orbits Khi V although it is almost completely destroyed with its antennae ripped off. Khi V has one large moon that is almost the same size as Khi V that creates a lot of tidal forces which creates a subsurface ocean. The surface of Khi V is almost perfectly smooth from the constant shifting of the crust.

Khi VI
Khi VI is a small planet with a thick atmosphere consisting of 97% nitrogen and the other 3% consisting of various gasses including methane, ethane, and hydrogen. Khi VI has had multiple probes sent to it including 1 lander and a submarine. Khi VI has oceans, rivers and lakes of liquid methane and ethane.