Discovering transiting exoplanets with long orbital periods allows us to
study warm and cool planetary systems with temperatures similar to the planets
in our own Solar system. The TESS mission has photometrically surveyed the
entire Southern Ecliptic Hemisphere in Cycle 1 (August 2018 - July 2019), Cycle
3 (July 2020 - June 2021) and Cycle 5 (September 2022 - September 2023). We use
the observations from Cycle 1 and Cycle 3 to search for exoplanet systems that
show a single transit event in each year - which we call duotransits. The
periods of these planet candidates are typically in excess of 20 days, with the
lower limit determined by the duration of individual TESS observations. We find
85 duotransit candidates, which span a range of host star brightnesses between
8 < Tmag < 14, transit depths between 0.1 per cent and 1.8 per cent, and
transit durations between 2 and 10 hours with the upper limit determined by our
normalisation function. Of these candidates, 25 are already known, and 60 are
new. We present these candidates along with the status of photometric and
spectroscopic follow-up.Comment: 25 pages, 16 figures, submitted to Monthly Notices of the Royal
Astronomical Societ