A persistent periodic process matches the HD 111232 signal in 32 later velocities at a fixed 19.68-day period
We test whether a periodic process trained on older velocities can predict the selected 19.68-day signal in HD 111232. We use 85 HARPS nights from 2004–2021 and 32 later ESPRESSO and HARPS time bins from 2024–2025. The period is fixed to the earlier search value. We remove the same long-period background and smooth terms in each comparison. A two-harmonic Gaussian process with infinite coherence, trained only on the older data, gives a later negative log predictive density of 25.257. The fixed Kepler curve gives 25.081 at the same added later white noise of 0.55 m/s. Shorter coherence gives poorer forecasts. Two alternative smooth background models give process-minus-Kepler score differences below 0.35. Training on the other HARPS reduction gives a difference of 1.88. The persistent process is exactly a harmonic regression with a Gaussian prior. Its success does not establish a stellar cause. This exploratory reanalysis uses a period and a target already selected for later agreement. It shows that this phase agreement alone does not identify the physical cause when an unrestricted persistent periodic process is allowed. The package includes the frozen data subset, source provenance, code, figures, numerical checks, and all simulation statistics.
HD 111232 · radial velocity · Gaussian process · periodic signal · stellar activity · prediction · public data
References
8- usesA blind Keplerian search of 743 HARPS-RVBank v2 stars with 30 or more nights recovers 248 of 465 known planets and finds 57 signals (FAP < 0.1 %) with no known match that pass activity tests sci:sha256:17e2629023ac1bcbb507eb643afc93a73a34d8a9d1ba2357cc22bd7bc4f108cb
We use the 85 HD 111232 HARPS nights, the three fixed curves, and the selected 19.68-day period. We test a persistent periodic process at that period.
- usesIndependent RVs reject 13 of 25 testable HARPS-RVBank v2 candidates (3 if HARPS errors double) and agree with a 19.7-day HD 111232 signal, with linear-trend nuisance models sci:sha256:1b429149b29b478f8b85a22182153f1e36c4ea06d284bbeb276a362b6f2254b1
We use the selected ESO records and source retrieval code. We test how correlated periodic noise changes the interpretation of the same later phase agreement.
- usesdoi:10.1051/0004-6361/202348263
HARPS-RVBank v2 supplies the older velocities and the two reductions of the same spectra.
- usesdoi:10.26093/cds/vizier.36830125
We query the HD111232 rows of table4 to compare the SERVAL and DRS reductions.
- doi:10.1093/mnras/stv1428
This paper describes Gaussian process models for stellar activity in radial velocities. Our two-harmonic process is a statistical sensitivity model, not a physical activity fit.
- doi:10.3847/1538-4365/ac7e57
This work gives context for the known long-period companions of HD 111232.
- doi:10.3847/1538-3881/ac9126
The conflict between a Gaia orbit and radial velocity data motivates care with the long-period background.
- doi:10.1051/0004-6361/201936686
This work describes the HARPS SERVAL velocities used by HARPS-RVBank.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- Approximate 95% bounds from 26 ESPRESSO profiles are below 1.33 m/s for six HD 111232 blend models with independent errors
This prior study showed the limits of identifying physical causes from phase agreement.
- Five TESS sectors recover 495 of 500 circular test transits of 1.25 Earth radii near 19.68 days in HD 111232 with a fixed star model and impact parameters 0–0.8
Its persistent-process result shows why agreement between velocity curves does not by itself identify a planetary cause.
- A 19.68-day model fits 26 ESPRESSO velocities of HD 111232 better than eight tested aliases under independent Gaussian noise
This study shows that a persistent process can predict the fixed-period signal. Period preference alone cannot identify its cause.