NEID radial velocities of TOI-5126 and TOI-5398

In particular, it is of great interest whether the large spin-orbit misalignments observed are driven primarily by high-eccentricity migration-expected to have occurred for short-period, isolated planets-or reflect a more universal process that operates across systems with a variety of present-day architectures.

Compact multiplanet systems offer a unique opportunity to differentiate between these competing hypotheses, as their tightly packed configurations preclude violent dynamical histories, including high-eccentricity migration, allowing them to trace the primordial disk plane. In this context, we report measurements of the sky-projected stellar obliquity ({lambda}) via the Rossiter-McLaughlin effect for two sub-Saturns in multiple- transiting systems: TOI-5126 b ({lambda}=1+/-48{deg}) and TOI-5398 b ({lambda}=-8.1_-6.3_^+5.3^{deg}).