Brown dwarf stars and sunless rogue planets within five light years of Earth in Empire of the Solar Throne

In the universe of Empire of the Solar Throne, there are four brown dwarf stars plus a number of sunless rogue planets (lacking a star to orbit around) that have been targets of colonization via time-dilation-equipped starships (see Spaceships in Empire of the Solar Throne) since the Third Era (see timeline in Empire of the Solar Throne).