Fifteen Hypervelocity Stars Whose Gaia G Magnitudes are Less Than 16.0 and Radial Velocities Less Than—600 km per second

Abstract

From Gaia DR3 data using a simple search criteria fifteen hypervelocity stars (HVS) are detected. These stars have radial velocities less than −600 km s−1, Gaia G magnitudes less than 16.0 and Renormalized Unit Weight Error values less than 1.4. The U, V, W velocities also indicate that these stars are HVS. The effective temperatures of these stars indicate that they are F and G type stars. Gaia DR3 409420157955913856 and Gaia DR3 2198292118993038464 seems to be metal-poor HVS. High resolution spectroscopy of these stars is needed to derive the atmospheric parameters, chemical composition and to understand their evolutionary status and origin. The progenitors of these stars may be close binary systems with white dwarf companions. When the white dwarf companions became Type Ia supernovae and their F-G companion stars have become HVS. Or they may be the result of other unknown processes.