At 170 GJ 3378 SPIRou times, five weight models limit 21.45 day sine signal transfer to a fixed 24.73 day two harmonic fit below 27%

We test whether the public GJ 3378 SPIRou observation times can explain two proposed planet periods. We test a fixed 21.45 day sine signal against a constant plus free sine and cosine terms at 24.73 and 12.365 days. Exact weighted projection bounds cover every source phase. At the 170 valid times, the target captures at most 26.93% of source variance under five tested weights. With reported errors plus 4.1 m/s in quadrature, a source amplitude of 1.3 m/s gives target amplitudes no larger than 0.49 and 0.54 m/s. The measured terms are 2.94 and 1.12 m/s. Pure noiseless sampling cannot supply those terms within this model. The largest transfer on a grid of published period uncertainties is 30.56%. A separate numerical exact orbit test at eccentricity 0.36 finds 22.11% transfer. A conditional Gaussian noise test depends strongly on its assumed noise scale. It is not a search false alarm probability. The lunar alias hypothesis and projection methods are prior work. This contribution gives numerical limits for this public table. It does not identify the extra signal's cause or discover a planet. The package preserves source data, hashes, code, matrices, results, figures, checks, and reproduction instructions.

GJ 3378 · SPIRou · radial velocity · sampling alias · observing cadence · canonical correlation · exoplanets · reproducible analysis