Questar M-17
Questar M-17 was an object beyond the fringe of the Milky Way Galaxy. It was believed to be the source of mysterious radio emissions until 2269, when during a star charting mission heading on an outward course towards it, the  was drawn off course towards the real source, an unusual dead star. ()

Appendices

Background information 
According to Star Trek: Star Charts (p. 13) and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), "Quasar M17" was located in the Beta Quadrant, at the fringe of the Milky Way Galaxy, near the galactic barrier.

Apocrypha 
According to Star Trek Maps ("Chart A"), Questar M17 was located near the disputed border between the  and the Tholian Assembly on the Federation side.

External link 
 

de:Questar M-17
Stars