We present proper motions, radial velocities, and a photometric study of the Galactic open cluster NGC?7380, which is associated with prominent emission nebulosity and dark molecular clouds. On the basis of the sample of highly probable member stars, the star cluster is found to be at a distance of 2.6 ± 0.4?kpc, has an age of around 4?Myr, and a physical size of ~6?pc across with a tidal structure. The binary O-type star DH?Cep is a member of the cluster in its late stage of clearing the surrounding material, and may have triggered the ongoing star formation in neighboring molecular clouds which harbor young stars that are coeval and comoving with, but not gravitationally bound by, the star cluster.
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