14 CARMENES observations support the fixed signal at 19.466 days in GJ 720 A under Gaussian white noise

We test the reported orbit of GJ 720 A b with public CARMENES DR1 velocities. We hold the period at 19.466 days and fix the other orbital elements to the published central values. Two of 16 observations have a daytime flag. We use the 14 clean observations and fit an offset, a signed amplitude, and extra Gaussian white noise. The fitted amplitude is 6.15 m/s. Its nominal 95% profile interval is 3.97 to 8.38 m/s. A calibration at the fitted noise model gives an interval of 3.69 to 8.68 m/s. Each null test uses 10000 simulated datasets with the noise scale fitted again. The no orbit test gives p=0.00020. The published amplitude of 4.72 m/s gives p=0.2378. All 44 fixed correlated noise cases have nominal profile intervals above zero. Activity, sampling, epoch, trend, and archive correction controls also retain positive amplitudes. This result adds evidence from a separate instrument for the known velocity signal. It does not establish a new planet or exclude stellar activity. The probabilities assume the fitted Gaussian white noise model. The source orbital uncertainties are not jointly propagated. The package has code, derived data, figures, simulation arrays, provenance, and a hash-checked source download.

GJ 720 A · CARMENES · radial velocity · exoplanet · stellar activity · independent instrument · public data