Constellations is a character progression system in Genshin Impact. Constellations upgrade the playable character's talents/skills by altering its effects or by further increasing its stats, effects, and passive buffs. In order to unlock a constellation, you will need to obtain a Stella Fortuna material that can only be obtained from pulling a duplicate character via Wishes. This page covers a list of all the constellations found in each playable character in the game.
Genshin Impact Constellations
Jean
Amber
Lisa
Kaeya
Barbara
Diluc
Razor
Venti
Klee
Bennett
Noelle
Fischl
Xiao
Beidou
Ningguang
Xiangling
Xingqiu
Sucrose
Mona
Chongyun
Qiqi
Kequing