Dynamics of wide binary stars: A case study for testing Newtonian dynamics in the low acceleration regime

Understand

Extremely wide binary stars represent ideal systems to probe Newtonian dynamics in the low acceleration regimes (<10e-10 m/s/s) typical of the external regions of galaxies.

• Here we present a study of 60 alleged wide binary stars with projected separation ranging from 0.004 to 1 pc, probing gravitational accelerations well below the limit were dark matter or modified dynamics theories set in.
• Radial velocities with accuracy ~100 m/s were obtained for each star, in order to constrain their orbital velocity, that, together with proper motion data, can distinguish bound from unbound systems.
• It was found that about half of the observed pairs do have velocity in the expected range for bound systems, out to the largest separations probed here.