Meet the Fellows Research Increasing the number of confirmed young planets with robust mass measurements to test models of how rapidly planets form and evolve. Host University Yale University Year Awarded 2024 Website Professional Page Quang H. Tran Ph.D. candidate, Astronomy, University of Texas at Austin Research Increasing the number of confirmed young planets with robust mass measurements to test models of how rapidly planets form and evolve. Host University Yale University Year Awarded 2024 Website Professional Page “Today we have some advanced techniques and statistical frameworks for modeling exoplanets—but people are getting different results. We need more observations and new methods to robustly characterize these systems and understand what might be missing from existing theories and models.” quang h. tran Catching young gas giant exoplanets in the act of becoming Hot Jupiters (classes of gas giant exoplanets physically similar to Jupiter with high surface-atmosphere temperatures) would help explain how these massive orbs wind up shockingly close to their parent stars. However, their notoriously active stars mimic and mask planet signals, making it hard to detect them. Quang Tran compares the “noisy” light of these still-developing stars to the sounds of a screaming human baby. Mr. Tran realized he could decrease stellar activity noise significantly by using infrared frequencies. He demonstrated this approach using the Habitable-Zone Planet Finder, one of the few instruments capable of capturing near-infrared wavelengths at high precision and resolution. One of Mr. Tran’s simulations models stellar activity signals over periods of time in both photometry and radial velocity. By finding and characterizing more giant exoplanets in this way, Mr. Tran aims to clarify the nature and timing of Hot Jupiters as they migrate toward their host stars. What he learns may explain conflicting results across prevailing theories, models, and observations. During his fellowship, Mr. Tran will combine existing surveys of young stars to locate enough giant exoplanets in this age range for meaningful comparisons with older planets of similar size and proximity to their host stars. He will also apply his near-infrared radial velocity technique with photometry from the TESS space telescope and statistical modeling to measure the masses for this largest-ever sample of young, giant planets. In doing so, Mr. Tran will extend the timeline of observed planets’ formation backward—and bring forward understanding of their histories, and our own. Mr. Tran will receive a Ph.D. in astronomy from the University of Texas at Austin in Spring 2024.