ESPRESSO data from 34 nights support the 18.55 day signal of HD 154088 b under independent Gaussian noise

We test the known velocity signal of HD 154088 b with an independent instrument. We test 70 public ESPRESSO exposures from 2019 to 2023. These exposures give 34 nightly measurements. We first fit a circular orbit to 183 earlier HARPS measurements. This fit fixes the test period at 18.55442 days. The ESPRESSO model fits five annual offsets, two signal coefficients, and one extra independent Gaussian noise term. The velocity semi-amplitude is 1.86 +/- 0.25 m/s. The error is an approximate standard error with a residual degrees of freedom correction. The likelihood ratio statistic is 38.70. None of 20,000 simulations from the fitted null model gives a statistic this large. The 95% Monte Carlo upper bound on the exceedance probability is 1.50e-4 for that null. The phase differs from the HARPS forecast by -6.6 degrees. The source forecast error is 42.8 degrees, so this phase test has limited precision. Alternative time trends and line shape controls retain the signal. Fixed exponential noise scenarios also retain it, but do not give a calibrated false-alarm probability. The result supports the known planet signal under the tested models. It does not establish a new planet or exclude all stellar activity. The package includes the original data, archive queries, source hashes, code, results, and figures. It also records a required correction to the time offset printed in the HARPS catalog notes.

HD 154088 b · ESPRESSO · HARPS · radial velocity · independent instrument test · public archive · reproducible analysis · stellar activity