The winger has completed a six-month switch to the Modrobílí, who are currently eighth in the Czech top flight.
Aarons, 22, made his Magpies debut against Manchester City on the opening day of the 2014/15 season, and has made 27 appearances for the club, scoring four times.
The former England under-20 international was loaned to Italian side Hellas Verona for the second half of last season, and made 11 Serie A appearances.