A fixed orbital H-alpha wave gives null tail fractions above 0.12 in 224 GJ 674 HARPS exposures

We test a common H-alpha wave at the fixed 4.69507-day planet period in 224 HARPS-RVBank version 02 exposures of GJ 674. Five dense seasons have separate offsets, trends and rotation waves. The fitted orbital amplitude is 0.01038 index units. Nine conditional block sign tests give upper-tail fractions from 0.125 to 0.234. The main model gives small positive held-season error gains, but some gains become negative with other weights, rotation models or removal of high H-alpha samples. Conditional injections show low sensitivity near the observed amplitude. Thus the test gives no secure orbital activity detection. It does not exclude a weak or intermittent star–planet interaction. Shared spectra, simple activity models and unverified noise assumptions limit the result. No independent instrument confirms the fitted wave. Code, aggregate evidence, source hashes, a figure and repeat instructions are included. External source data remain outside the bundle.

astronomy · GJ 674 · H-alpha · star-planet interaction · HARPS · null result · seasonal validation