The light echo of an X-ray flare from the nucleus of a galaxy has been observed. The flare almost certainly originates from a single star being gravitationally ripped apart by a supermassive black hole in the galactic core. As the star was being pulled into the black hole, its material was injected into the black [...]

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How do astronomers determine with certainty the X-ray source location when they point the X-ray detecting telescopes in a particular direction. As there could many X-ray sources given a particular direction or the sources may even share the same galactic sky co-ordinates separated only by distances.

The source is the point from which it eminates.

How can you tell a stars direction?
You don't even need a telescope- Just Look Up
Granted- this only tells us where that star was at the time the light we are seeing left that star.