  Ground-based wide-field surveys for nearby transiting gas giants are yielding
far fewer true planets than astrophysical false positives, of which some are
difficult to reject. Recent experience has highlighted the need for careful
analysis to eliminate astronomical systems where light from a faint eclipsing
binary is blended with that from a bright star. During the course of the
Trans-atlantic Exoplanet Survey, we identified a system presenting a
transit-like periodic signal. We obtained the proper motion and infrared color
of this target (GSC 03885-00829) from publicly available catalogs, which
suggested this star is an F dwarf, supporting our transit hypothesis. This
spectral classification was confirmed using spectroscopic observations from
which we determined the stellar radial velocity. The star did not exhibit any
signs of a stellar mass companion. However, subsequent multi-color photometry
displayed a color-dependent transit depth, indicating that a blend was the
likely source of the eclipse. We successfully modeled our initial photometric
observations of GSC 03885-00829 as the light from a K dwarf binary system
superimposed on the light from a late F dwarf star. High-dispersion
spectroscopy confirmed the presence of light from a cool stellar photosphere in
the spectrum of this system. With this candidate, we demonstrate both the
difficulty in identifying certain types of false positives in a list of
candidate transiting planets and our procedure for rejecting these imposters,
which may be useful to other groups performing wide-field transit surveys.
