Tara Fetherolf (UC Riverside): "Sinusoidal Stellar Variability Catalog of Stars Observed During the TESS Primary Mission"

Title: Sinusoidal Stellar Variability Catalog of Stars Observed During the TESS Primary Mission

Abstract: The shape and periodic nature of stellar light curves can uncover important information about a star’s intrinsic properties, in addition to revealing possible companions. TESS has obtained high-precision space-based time-series photometry of nearly the entire sky, allowing for a large-scale study of stellar variability that is not sensitive to the diurnal limitation of ground-based surveys. We searched for periodicity in ~230,000 stars that were observed at 2-minute cadence during the TESS primary mission and identified ~55,000 stars with significant sinusoidal variability on timescales of 0.01-13 days that could be attributed to rotational modulations, stellar pulsations, or binarity. During this talk, I will show some of our preliminary results, including the population statistics for stars in our sinusoidal stellar variability catalog. The variability of known planet host stars will also be highlighted, which we use to identify exoplanets that exhibit atmospheric phase variations or are potentially false positives due to stellar activity. Our stellar variability catalog will be a valuable resource to the stellar astrophysics and exoplanet communities, in that it will aid 1) studying the characteristics of periodic variable stars; 2) understanding interactions between host star variability and planetary atmospheres; and 3) identifying false positives caused by stellar variability for future planet candidates. At the end of my talk, I will also briefly highlight my dissertation work, where I investigated how the distribution of stars and dust evolves in high-redshift galaxies using a new morphology metric, called “patchiness.”