Determining The Ephemerides of TESS Single Transits Using Archival Photometric Data And RV Monitoring

@mastersthesis{yao2020,
  title = {Determining The Ephemerides of TESS Single Transits Using Archival Photometric Data And RV Monitoring},
  author = {Yao, Xinyu},
  year = {2020},
  month = aug,
  publisher = {Lehigh University},
  keywords = {Data Analysis, Exoplanet Detection, Radial Velocity, Transiting,},
  abstract = {Exoplanets with a long orbital period provide insight about different thermal and dynamical environments than those of shorter-period planets; however, in many cases, we can only detect single transits for them. The ephemerides are challenging to determine from only single transit events. The ability to determine the precise ephemerides for these systems is valuable and essential to plan the photometric follow-up and transmission \& emission spectroscopy observations.The Transiting Exoplanet Survey Satellite (TESS) will detect hundreds of planets with long orbital periods with single transits in their TESS light curves. The goal of this dissertation is to explore the use of existing ground-based wide-field photometric surveys to constrain the ephemerides of the TESS single-transit candidates, with a focus on the Kilodegree Extremely Little Telescope (KELT) survey. We insert simulated TESS-detected single transits into KELT light curves, and evaluate how well their orbital periods can be recovered. We find that KELT photometry can be used to confirm ephemerides with high accuracy for planets of Saturn size or larger with orbital periods as long as a year, and therefore span a wide range of planet equilibrium temperatures. In a large fraction of the sky we expect to recover 30\% to 50\% of warm Jupiter systems (planet radius of 0.9 to 1.1 RJ and 13:5 < P < 50 days), 5\% to 20\% of temperate Jupiters (50 < P < 300 days), and 10\% to 30\% of warm Saturns (planet radius of 0.5 to 0.9 RJ and 13:5 < P < 50 days).In addition, we explore the use of Radial Velocity (RV) follow-up observations in the case of single transit events. We find that the use of the estimated period based on a circular orbit to schedule reconnaissance RV observations around quadrature can efficiently distinguish EBs from planets. For candidates that pass reconnaissance RV observations, we simulate RV monitoring campaigns cross three months to obtain an orbital solution. We find this method is efficient to calculate orbital solution for planets more massive than 0.5MJ with orbital periods as long as 100 days.The resulting ephemerides can be used for follow-up observations to confirm candidates as planets, eclipsing binaries, or other false positives, as well as to conduct detailed transit observations with facilities like JWST or HST.},
}