QSO candidates in OGLE-II data

This search used the optical variability properties of point sources from the Magellanic Cloud OGLE-II photometric data. Objects bluer than V-I=0.9mag and within 17mag<I<20.5mag were studied.

Robust variograms/structure functions have been computed for each time-series and only candidates showing a significantly increasing variability over longer time scales were selected. Several light curves were identified as having probable artifacts and were therefore removed. Stars showing signs of periodicity or small trends in their light curves were also removed and we are left with mostly either Be stars ({gamma} Cas stars) or QSO candidates.