A PSF-based Approach to TESS High quality data Of Stellar clusters
  (PATHOS) -- I. Search for exoplanets and variable stars in the field of 47
  Tuc
  The TESS mission will survey ~85 % of the sky, giving us the opportunity of
extracting high-precision light curves of millions of stars, including stellar
cluster members. In this work, we present our project "A PSF-based Approach to
TESS High quality data Of Stellar clusters" (PATHOS), aimed at searching and
characterise candidate exoplanets and variable stars in stellar clusters using
our innovative method for the extraction of high-precision light curves of
stars located in crowded environments. Our technique of light-curve extraction
involves the use of empirical Point Spread Functions (PSFs), an input catalogue
and neighbour-subtraction. The PSF-based approach allows us to minimise the
dilution effects in crowded environments and to extract high-precision
photometry for stars in the faint regime (G>13). For this pilot project, we
extracted, corrected, and analysed the light curves of 16641 stars located in a
dense region centred on the globular cluster 47 Tuc. We were able to reach the
TESS magnitude T~16.5 with a photometric precision of ~1 % on the 6.5-hour
timescale; in the bright regime we were able to detect transits with depth of
~34 parts per million. We searched for variables and candidate transiting
exoplanets. Our pipeline detected one planetary candidate orbiting a main
sequence star in the Galactic field. We analysed the period-luminosity
distribution for red-giant stars of 47 Tuc and the eclipsing binaries in the
field. Light curves are uploaded on the Mikulski Archive for Space Telescopes
under the project PATHOS.
