Gravitational Anomaly Measurement in Wide Binaries is Sensitive to Orbital Modeling
Abstract
Recent work by Chae et al. (2026) reported a gravitational anomaly in 36 wide-binary pairs, finding a gravity boost factor of at low accelerations, consistent with predictions from Modified Newtonian Dynamics (MOND). We reanalyze the same dataset using a hierarchical Bayesian model that infers a global across all systems while fitting three-dimensional orbital elements. Our model yields , consistent with Newtonian gravity () at the level. To identify the source of the discrepancy, we perform a test using an approach similar to Chae et al. (2026), replacing the semi-major axis with a geometric de-projection of the observed projected separation. This test yields , closely matching the result of Chae et al. (2026). This suggests that the inferred value of is sensitive to how the three-dimensional orbital separation is modeled, and including an independent semi-major axis parameter can account for velocity excesses that would otherwise be attributed to non-Newtonian gravity.
Cite
@article{arxiv.2603.11015,
title = {Gravitational Anomaly Measurement in Wide Binaries is Sensitive to Orbital Modeling},
author = {Serat M. Saad and Yuan-Sen Ting},
journal= {arXiv preprint arXiv:2603.11015},
year = {2026}
}
Comments
10 pages, 4 figures. Submitted to OJAp