A survey of the coldest planets around low-mass stars

The exoplanet community is eagerly searching data from the Transiting Exoplanet Survey Satellite (TESS) for M dwarfs hosting small planets in their habitable zones. For my thesis work, I plan to look beyond the habitable zone to find the coldest planets orbiting M dwarf stars to determine their occurrence rate. To identify these planets in the TESS (and potentially K2) light curves, I am designing a pipeline recognizing both single- and multiply-transiting long-period planets. As nearly half of these long-period planets will be detected as single-transit events, I look to the TESS extended mission to recover second transits for many of these targets which will then offer the potential to find their true periods through ground based follow-up. I will quantify the completeness and reliability of my pipeline by implementing injection/recovery tests. I will then calculate the occurrence rate of cold M dwarf planets as a function of orbital period and planet radius. By studying this hitherto underexplored area of parameter space, this work can be applied towards understanding the demographics of cold M dwarf planets as well as providing candidates for future mass and atmospheric characterization. Based on a simulated planet catalog (Barclay et al., 2018), I anticipate 27 single-transiting and 32 multiply-transiting M dwarf planets with P > 20 days from the TESS primary mission. I hope to have early results at the time of this meeting.