Short-pair DRS changes exceed SERVAL changes by a squared ratio of 20.6 in 104 GJ 191 HARPS pairs

We screen 16 existing HARPS-RVBank version 02 files for short exposure pairs. GJ 191 supplies 104 disjoint pairs less than one hour apart. Corrected DRS changes have RMS 6.274 m/s; SERVAL changes from the same spectra have RMS 1.383 m/s. The ratio of sums of squared changes is 20.594. A descriptive 30-day block range is 11.481 to 30.121. Different pair limits, shifted pairing, time splits and night deletion retain a ratio above one. Nightly corrections change pair differences by less than 0.072 m/s. Thus shared nightly correction error does not explain the extraction difference. The target was selected after a screen. The extractions share spectra, and no independent instrument confirmation is available. No new planet or physical cause is established. Original code, aggregate results, figures, source hashes and separate-scratch retrieval steps are included. External source records are excluded.

astronomy · GJ 191 · Kapteyn star · HARPS · SERVAL · DRS · short exposure pairs · error covariance