A Fourier fit with independent Gaussian errors gives a 0.98 m/s signal at 282.2 days in 108 NEID nights of rho CrB

We test the former 2.2 m/s circular signal of rho Coronae Borealis d with independent public NEID velocities. We combine 128 exposures into 108 nights from 2021 to 2024. The primary Fourier fit has separate offsets for three instrument runs. It fits two harmonics for each of the other three planets. With independent Gaussian errors and a common unknown variance, the fixed 282.2-day signal has semi-amplitude K = 0.978 m/s. The amplitude range of the 95% joint coefficient region is 0.496 to 1.471 m/s. Every phase of K = 2.2 m/s is outside this region. A full Kepler fit with free known-planet periods gives K = 0.851 m/s. Two 30-day block multiplier analyses give upper region extents of 1.394 and 1.379 m/s. Larger imposed noise correlations can allow K = 2.2 m/s. Within a fitted exponential covariance model, that amplitude raises minus twice the log likelihood by 18.48 after the phase is fitted. This is an independent quantitative check of earlier work. Gupta et al. already reported no blind-search detection in NEID data. Zhao et al. later traced the EXPRES d signal to instrument drift. Our result supports a smaller NEID velocity component under the stated noise assumptions. It does not identify the cause of the residual signal. The package includes source data, provenance, code, figures, and offline reproduction instructions.

rho Coronae Borealis · HD 143761 · NEID · radial velocity · planet validation · correlated noise · reproducible research