Van Maanen's star

A white dwarf star of about .7 solar masses, some 14 light-years away from Sol before it was destroyed in the Maanen incident, several years before the Solarian Purge, and had been settled by the Pisces Mission.

It had three stargates, undergoing activation, to 61 Cygni, Tau Ceti, and Epsilon Eridani. They were destroyed along with their host star, and most of the Pisces Mission along with them.