  This paper presents the case of CoRoT LRa02_E2_0121, which was initially
classified as a Neptune-size transiting-planet candidate on a relatively wide
orbit of 36.3 days. Follow-up observations were performed with UVES, Sandiford,
SOPHIE and HARPS. These observations revealed a faint companion in the spectra.
To find the true nature of the system we derived the radial velocities of the
faint companion using TODMOR - a two-dimensional correlation technique, applied
to the SOPHIE spectra. Modeling the lightcurve with EBAS we discovered a
secondary eclipse with a depth of ~0.07%, indicating a diluted eclipsing
binary. Combined MCMC modeling of the lightcurve and the radial velocities
suggested that CoRoT LRa02_E2_0121 is a hierarchical triple system with an
evolved G-type primary and an A-type:F-type grazing eclipsing binary. Such
triple systems are difficult to discover.

Earth and Planetary Astrophysics;Solar and Stellar Astrophysics