Postdoctoal associate Xian-Yu Wang and graduate students Armaan Goyal, Brandon Radzom, and Emma Dugan all attended the Emerging Researchers in Exoplanets Conference IX (ERES IX) at Cornell University, July 10-12, and presented their research. ERES, is an annual conference focused on bringing together early-career exoplanet astronomers, including undergraduates, graduate students, and post-docs. In addition to a full science program of talks and poster sessions, the program featured professional development opportunities in the form of a career panel and a panel on the decadal survey.
Xian-Yu Wang spoke about prevalent spin-orbit alignment of warm Jupiters in single-star systems around hot stars. He presented Rossiter-Mclaughlin effect measurements for six warm Jupiters, demonstrating that all of them are aligned, regardless of their stellar effective temperature. This pattern diverges from the trend observed in hot-Jupiter systems, where hot Jupiters around cool stars tend to be aligned, while a considerable proportion of those orbiting hot stars show misalignment. The current distribution of stellar obliquity for Jovian exoplanets suggests that misalignments are not universal or primordial phenomena affecting all planet types. The absence of misalignments in warm Jupiter systems further implies that many hot Jupiters, in contrast, have experienced dynamic and violent histories.
Armaan Goyal presented his research on “peas-in-a-pod” across the radius valley, presenting the first direct statistical comparison of intra-system planetary uniformity across compositionally distinct regimes, based upon the separate architectural evaluation of systems containing only small (Rp ≤ 1.6R⊕), rocky planets from those harboring only intermediate-size (1.6R⊕ ≤ Rp ≤ 4R⊕), volatile-rich worlds. Compared to their volatile-rich counterparts, rocky systems are more uniform in size, less uniform in mass, and more uniform in spacing at respective significance levels of 4.0σ, 2.6σ, and 3.0σ.
Brandon Radzom spoke about the alignment of stellar spin axes with the orbit normal axes of planetary orbits, hoping to distinguish whether such large obliquities are produced primarily by high-eccentricity migration or a more universal process that affects systems with a wider array of present-day architectures. He reported on Rossiter-McLaughlin effect measurements of the sky-projected stellar obliquity for two sub-Saturns, TOI-5126 b and TOI-5398 b, and one hot Jupiter, TOI-5143 b, all found to reside in multiple-transiting systems; all three are spin-orbit aligned. When combined with archival data, these results demonstrate a strict trend of alignment for compact systems, providing strong observational support for primordial alignment and post-disk misalignment via high-eccentricity migration pathways.
Emma Dugan presented a poster on the universal misalignments of sub-Saturn exoplanets. She presented two new stellar obliquity measurements of warm sub-Saturn planets, both of which are misaligned. Integrating these results with archival data reveals that sub-Saturn planets, in contrast to Jupiters, consistently exhibit misalignment irrespective of their host star’s temperature or orbital period. This finding introduces a compelling new puzzle and imposes significant constraints on our understanding of the origins and evolution of spin-orbit misalignment
2024 ERES IX Conference Participants
From Left to Right: Post Doctoral Fellow Xian-Yu Wang, Graduate Student Brandon Radzom, Graduate Student Emma Dugan, and Graduate Student Armaan Goyal.
The College of Arts