  Context: Multiple stellar systems are unique laboratories for astrophysics.
Analysis of their orbital dynamics may reveal invaluable information about the
physical properties of the participating stars. Unfortunately, there are only a
few known and well described multiple systems, this is even more so for systems
located outside the Milky Way galaxy. A particularly interesting situation
occurs when the inner binary in a compact triple system is eclipsing. This is
because the stellar interaction, typically resulting in precession of orbital
planes, may be observable as a variation of depth of the eclipses on a long
timescale. Aims: We aim to present a novel method to determine compact triples
using publicly available photometric data from large surveys. Here we apply it
to eclipsing binaries (EBs) in Magellanic Clouds from OGLE III database.
Methods: We analyzed light curves (LCs) of 26121 LMC and 6138 SMC EBs with the
goal to identify those for which the orbital inclination varies in time.
Archival LCs of the selected systems, when complemented by our own observations
with Danish 1.54m telescope, were thoroughly analyzed using the PHOEBE program.
Time dependence of the EB's inclination was described using the theory of
orbital-plane precession. By observing the parameter-dependence of the
precession rate, we were able to constrain the third companion mass and its
orbital period around EB. Results: We identified 58 candidates of new compact
triples in Magellanic Clouds. This is the largest published sample of such
systems so far. Eight of them were analyzed thoroughly and physical parameters
of inner binary were determined together with an estimation of basic
characteristics of the third star. These data may provide important clues about
stellar formation mechanisms for objects with different metalicity than found
in our galactic neighborhood.
