A recent confirmation of the wide binary gravitational anomaly

• Published in: Monthly notices of the Royal Astronomical Society
• Main Authors: Hernandez, X, Kroupa, Pavel
• Format: Journal Article
• Language: English
• Published: 14.02.2025
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/staf210

Concerning recent published studies exploring the presence or otherwise of a gravitational anomaly at low accelerations in wide binary stars as observed by the Gaia satellite, the paper published by Cookson on the subject last year presents an interesting case. In that study, RMS values of binned relative internal velocities in 1D for wide binaries are compared to Newtonian predictions for that quantity, with the author concluding that the data presented show no indication of any inconsistency with Newtonian expectations. However, the comparison presented is critically flawed, as the Newtonian predictions used refer to wide binaries with mean total masses of 2.0 M⊙. This is larger than the 1.56 M⊙ value which applies to the data used in said paper. In this short note we correct the error mentioned above and show that the data and error bars as given by Cookson are in fact inconsistent with Newtonian expectations. Contrary to the assertion in that study, the data presented there actually show a clear anomaly in the low acceleration gravitational regime, with the overall slope of the velocity-separation scaling being inconsistent with Newtonian expectations at a 3.3σ level. Based on the data presented in the paper by Cookson, wide binary systems show a clear Milgromian deviation from Newtonian dynamics.