The Gravitational Redshift of Solar-type Stars from Gaia DR3 Wide Binaries

Abstract Light escaping from a gravitational potential suffers redshift with magnitude proportional to the depth of potential. This “gravitational redshift” is easily measurable in dense stars such as white dwarfs, but much weaker and has evaded unambiguous detection main-sequence stars. I show that effect directly Gaia DR3 radial velocities (RVs) components wide binary In sample ∼500 binaries containing solar-type star red giant or clump companion, apparent RV on average 0.49 ± 0.02 km s −1 lower than star. owes primarily giants’ fields reasonably good agreement value expected general relativity.