Direct measurement of ISM proper motion with image registration

To date, the quantification of the on-sky motion for interstellar clouds has relied on proxies such as young stellar objects (YSOs) and masers. We present the first direct measurement of an interstellar cloud proper motion using the VISTA Star Formation Atlas (VISIONS) multi-epoch infrared images of the Corona Australis star-forming region. Proper motions are extracted by tracking the morphology of extended structures in the cloud complex based on image registration techniques implemented in SimpleITK. Our determined values (μα* ∼ +15 mas yr−1, μδ ∼ −30 mas yr−1) are in good agreement with those obtained for YSOs and young stellar clusters in the region. This study demonstrates the potential of image registration for directly mapping the kinematics of nearby molecular clouds, opening a new window into the study of cloud dynamics.