A map of the Milky Way Galaxy
M80 was a globular cluster in the Delta Quadrant. It was located over 40,000 light years from the galactic core.
The location of M80 was shown on a computer panel in Astrometrics on USS Voyager during the later years of its seven-year journey in the Delta Quadrant. (VOY: "Endgame" display graphic [1])
The graphic is also shown (in legible detail) in Geoffrey Mandel's Star Trek: Star Charts.
According to the Star Trek: Star Charts (p. 82) and the Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), M80 was a quasar.
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