All 65 tested coplanar GJ 887 models at minimum masses with initial circular e and d orbits give less than 0.019 m/s at 2.21661 days after orbit fits

We test whether gravity between the four published GJ 887 planets can produce the reported 2.21661-day, 0.37 m/s candidate signal. We integrate Newtonian point-mass systems at public HARPS and ESPRESSO observation dates. We then fit four independent Kepler orbits and an added sine and cosine. The fits use two fixed choices of noise weights. At the published central values and minimum masses, the added amplitude is 0.002231 m/s with the published noise weights. Across 65 minimum-mass systems, the largest amplitude is 0.018741 m/s over both weight choices. The systems include the central values and 64 points in a box set by the published marginal errors. Larger true masses give a separate stress test. All 133 cases and numerical controls are preserved. The result limits this interaction explanation for the tested coplanar systems, initial circular orbits of planets e and d, and fitting method. The finite box is not a joint posterior or a continuous bound. The test does not fit measured velocities, confirm a fifth planet, or exclude other causes for the signal.

GJ 887 · radial velocity · planet interactions · Newtonian dynamics · planet candidates · public data · Kepler orbit fits