  Driven by the incomplete understanding of the formation of gas giant
extrasolar planets and of their mass-radius relationship, several ground-based,
wide-field photometric campaigns are searching the skies for new transiting
extrasolar gas giants. As part of the Trans-atlantic Exoplanet Survey (TrES),
in 2003/4 we monitored approximately 30,000 stars (9 .5 < V < 15.5) in a 5.7
degree x 5.7 degree field in Andromeda with three telescopes over five months.
We identified six candidate transiting planets from the stellar light curves.
  From subsequent follow-up observations, we rejected each of these as an
astrophysical false positive, i.e. a stellar system containing an eclipsing
binary, whose light curve mimics that of a Jupiter-sized planet transiting a
sun-like star. We discuss here the procedures followed by the TrES team to
reject false positives from our list of candidate transiting hot Jupiters. We
present these candidates as early examples of the various types of
astrophysical false postives found in the TrES campaign, and discuss what we
learned from the analysis.
