The Vega-Omicron sector was a sector of space that was, according to Jean-Luc Picard, located "in an obscure corner of the galaxy."
In 2365, the USS Aries picked up indications of intelligent lifeforms here, when the ship's captain retired and was due to be replaced by William T. Riker. Though Riker later declined, it would have taken him months at high warp from Starbase Montgomery to get to the Vega-Omicron sector. (TNG: "The Icarus Factor")