TOI-1135: Sub-Saturns are Universally Misaligned

Stellar obliquity measurements for Jupiter-sized planets reveal two patterns: cooler stars typically host hot Jupiters on aligned orbits, while hotter stars with hot Jupiters often show misalignments; additionally, hot Jupiters are more misaligned than their warmer counterparts. These observations underscore the importance of obliquity measurements for smaller planets like sub-Saturns, which provide a critical layer of constraints on the mechanisms driving spin-orbit misalignments, sensitive to planetary mass. The detection of sub-Saturns, especially warm ones, has been challenging due to their low occurrence and lower SNRs compared to larger gas giants. The TESS mission has significantly advanced this field by providing a statistically meaningful sample of sub-Saturns around bright stars. We present two new measurements of warm sub-Saturns, both misaligned, which, when combined with archival data, show that sub-Saturns are universally misaligned regardless of stellar temperature or orbital period. This discovery allows us to probe stellar obliquity in a previously uncharted domain, introducing a compelling new puzzle and imposing significant constraints on our understanding of the origins and evolution of spin-orbit misalignment.