Rare Exoplanet Transits Observed from Antarctica

Of the 870+ southern planetary candidates from TESS currently awaiting confirmation, roughly 10% have transit durations longer than five hours; over a third of these also have orbital periods longer than 20 days. Systems like these could fall into the sparsely populated parameter space of long-period gas giants; but long transits that happen infrequently present an observational challenge from the ground. Not so for ASTEP, a 40cm telescope installed at Dome C in Antarctica. ASTEP’s proximity to the South Pole means that it enjoys outstanding photometric conditions, as well exceptional phase coverage due to uninterrupted observing during the Austral Winter. In this poster I will share some results from ASTEP’s first seasons of SG1 observing, including uninterrupted 10 hour-long transits, TTV monitoring, and the first ever ground-based transit of a circumbinary planet.