Is the heliopause seen in radio synchrotron emission?

We present the first evidence that the interaction between the heliopause and the very local interstellar magnetic field results in radio synchrotron emission that is detected in 30~GHz polarization observations from Planck (Planck Collaboration et al., 2016). We examine stellar velocity patterns from the observed Gaia (Gaia Collaboration et al., 2021) barycentric proper motions, which include the peculiar motion of the Sun. We find that for nearby stars, the observed proper motions are dominated by the Solar motion and aligned with the magnetic field as traced by the Planck data. When these velocities are transformed into the local standard of rest frame, which removes the solar contribution, the pattern no longer matches the magnetic field, which demonstrates the connection to the motion of the Sun. We present evidence that the polarized emission traces the local interstellar magnetic field as it wraps around the heliosphere. This wrapping occurs at the heliopause boundary, which is related to the Sun's motion through space, and which has previously been revealed through the bright ribbon of emission detected by NASA’s Interstellar Boundary Explorer (IBEX) (McComas et al., 2009).