Independent error sums exceed measured one-day difference variance in 52 early and 42 late Ross 128 HARPS pairs

We compare changes between nights in the DRS minus SERVAL velocity difference for Ross 128 in HARPS-RVBank version 02. Independent quoted error sums exceed the measured squared changes in 52 early and 42 late selected pairs. Ratios are 0.579 and 0.702 for original products, and 0.503 and 0.319 for corrected products. Night selection and pairing controls retain the moment deficit in these groups. Block-bootstrap ranges depend on the time-bin width; the late original 10-day range includes one. Simulations show that shared extraction errors and errors that persist between nights can give the same ratio. These results do not measure extraction correlation alone, show that quoted errors are wrong, or establish an instrument change. No new planet or independently confirmed signal is found. Original code, aggregate results, figures, source hashes and external retrieval steps are included. Source records remain outside the baseline package.

astronomy · Ross 128 · HARPS · error covariance · radial velocity · negative control · noise calibration