Similar to millicenton, microcenton is used exclusively in an early episode, "Lost Planet of the Gods, Part II".
Starbuck tells Apollo, that he is "switching off of you for a microcenton to scan ahead." Considering that the early use of the centon in the pilot episode is something closer to a week, the microcenton would be somewhere in the neighborhood of a half second, or one millionth of a week.
The term is superseded by micron.