Overview

• Three-dimensional hydrodynamic simulations show that mergers of rare hybrid helium–carbon–oxygen white dwarfs can trigger a double detonation that ejects a surviving remnant at more than 2,000 km/s.
• The mechanism accounts for both the extreme speeds and the unusual temperatures and brightness observed in hypervelocity white dwarfs such as J0546 and J0927.
• The modeled explosions produce fast, faint thermonuclear transients that represent a potential channel for peculiar or underluminous Type Ia events.
• The research, led by Dr. Hila Glanz at the Technion with collaborators from Universität Potsdam and the Max Planck Institute for Astrophysics, appears in Nature Astronomy.
• The authors outline observational tests, with Gaia measurements and upcoming time-domain surveys expected to identify additional ejected remnants and associated faint explosions.