A fixed-period test finds no 4.388-day harmonic in 115 selected GJ 176 HARPS visits

We test the first eccentric harmonic of the known 8.776-day GJ 176 velocity wave in 115 selected HARPS-RVBank version 02 visits. A seasonal rotation model gives a 4.388-day amplitude of 0.163 m/s and a weighted loss decrease of 0.233. Four shared-sign noise tests give upper-tail fractions of 0.846 to 0.899. A second reduction and fixed model controls retain a weak harmonic. An exact orbit grid gives only a 0.316 loss decrease at its best eccentricity of 0.06. In a separate Gaussian experiment, the harmonic test detects 526 of 1000 exact 4 m/s orbits at eccentricity 0.2. Thus this null result does not establish a circular orbit. The two reductions share spectra. An independent data request timed out. No new planet or physical cause is established. Code, aggregate results, a figure, exact input hashes and external retrieval steps are included; the source database is excluded.

astronomy · GJ 176 · HARPS · eccentricity · harmonic · null result · injection recovery