VGSRF Seminar: Brandon Radzom (Indiana University) & Alex Rodriguez (UMich)

Brandon Radzom (Indiana University)

COUNTESS: A Pipeline to Extract the Potential of the TESS Mission for Exoplanet Demographics

Now in its third extended mission phase, NASA’s Transiting Exoplanet Survey Satellite (TESS) is well-positioned for comprehensive investigations of exoplanet demographics. Multiple sectors of coverage are now available for many targets, and numerous tools have been developed to enable deep (i.e., TESS magnitude < 13.5) transit searches over large samples of stars. Even still, exoplanet occurrence rate studies with TESS have each leveraged only a subset of these capabilities, limiting their scope. We present COUNTESS (Combining Observations to Unveil New Transiting Exoplanet Systems and Statistics), a new pipeline for light curve extraction, transit search, planet vetting, and occurrence rate calculations. COUNTESS maximizes the potential of the TESS mission for exoplanet demographics by integrating 1) reliable and lightweight light curve extraction for stars fainter than 13.5 magnitudes, 2) the capability to combine heterogeneously-sampled data from sectors spanning multiple mission phases, and 3) CPU and GPU-accelerated transit search and injection-recovery routines. Following our preliminary study, we will apply an updated version of COUNTESS to nearly 400,000 stars in the northern TESS Continuous Viewing Zone (CVZ) in search of new planets with orbital periods of up to several hundred days. Pushing to fainter limiting magnitudes significantly increases the number of CVZ stars that can be searched for transit signals, especially K and M dwarfs, enabling occurrence rate measurements for planets in the habitable zone. I also provide a brief overview of my dissertation research involving stellar obliquity measurements and numerical simulations to constrain the dynamical origins of hot Jupiters.

Alex Rodriguez (UMich)