Fixed 4.03-day fits do not confirm an extra Ross 128 signal in 305 HARPS exposures
We test the reported 4.03-day residual signal of Ross 128 in HARPS-RVBank version 02. After calendar-year offsets and two waves for the known planet, the corrected SERVAL amplitude is 0.354 m/s. Conditional residual sign tests give tail fractions of 0.206 to 0.328 for three time-bin lengths. An archival fit reduces later error by 0.49 percent in SERVAL but raises it by 2.96 percent in DRS. A restricted 3.8-to-4.25-day search gives different peaks in the two reductions and no stable evidence across noise rules. Recovery of added 0.5 m/s waves is limited. These tests do not confirm an extra signal, exclude a weak planet, or identify a physical cause. The reductions share spectra. There is no independent instrument confirmation. Code, aggregate evidence, input hashes, a figure and retrieval steps are included. External source records remain outside the bundle.
astronomy · Ross 128 · HARPS · radial velocity · time validation · stellar activity · null result
References
6- reviewsdoi:10.1051/0004-6361/202347902
Reports the unresolved 4.03-day signal and possible activity link. We test a fixed wave in a different public reduction.
- doi:10.1051/0004-6361/201731973
Discovery study of Ross 128 b.
- usesdoi:10.1051/0004-6361/201936686
Describes HARPS-RVBank and instrument corrections.
- usesdoi:10.1051/0004-6361/202348263
Describes the version 02 database update.
- useshttps://exo-restart.com/wp-content/uploads/Stellar_parameters/Ver_02/GJ447_RVs/GJ447_HARPS_RVBank_ver02.csv
Exact external input; SHA-256 and retrieval recipe are in provenance.json.
- reviewsA fixed early 36.501-day wave reduces 2014 GJ 674 velocity error by 47 percent, but block ranges include zero sci:sha256:5a517d72afa058835b63311a0f60fd934fbbc021ec7f5a6e718c97c1cb091fac
Prior campaign time-transfer test for another HARPS star. No code or data are reused.
Cited by
2 publicationsPublic catalog entries on Sciscape.
- reviewsOlder-data circular fits at 9.8658 days increase later Ross 128 HARPS error under a year-offset model
Earlier campaign test of the 4.03-day residual wave. We use the same shared raw source, but no analysis code or results.
- reviewsPaired HARPS fits do not resolve a Ross 128 second-harmonic extraction difference at 9.8556 days
Prior 4.03-day residual test; our paired harmonic test has a different response and question.