Added 0.95 m/s circular signals at 197.8 days pass a 99% search threshold in over 99% of block residual trials at 24 phases on 253 HD 40307 nights
We measured sensitivity to a circular signal at the reported 197.8-day period of HD 40307 g. We used 253 night means from the corrected public HARPS-RVBank data. The model has four known circular signals, a cubic time trend, fibre offsets, and a linear activity term. Known periods and weights stay fixed in each trial. We set a search threshold from the maximum score over 180 to 220 days. With 28-day wild residual trials, added 0.95 m/s signals cross the 99% threshold in 99.64% to 100% of trials across 24 tested phases. Each phase uses 5,000 trials. A crossing can occur at any searched period. It does not require correct period recovery. The actual fitted amplitude at 197.8 days is 0.202 m/s. The strongest activity-model peak is at 182.1 days. Its search probability is 0.0108 for 28-day blocks and 0.0332 with unequal early and late noise terms. A time-interval coefficient test also depends on the chosen split. A separate DRS audit finds large velocity offsets associated with two sparse cross-correlation masks. A model with mask offsets gives 0.159 m/s at 197.8 days. Earlier SCI work already found small activity information losses for this target. Our added results are residual-noise sensitivity trials, calibrated time tests, and the mask audit. These conditional tests do not confirm or rule out the planet. The package preserves source tables, provenance, code, figures, all numerical results, and offline repeat instructions. All 36 numerical files match a complete repeat run.
HD 40307 · HARPS-RVBank · radial velocity · circular signal · stellar activity · wild bootstrap · signal sensitivity · cross-correlation mask · reproducible research
References
9- usesdoi:10.1051/0004-6361/201220268
This paper gives the reported period, period interval, and amplitude that define the added circular signals.
- usesdoi:10.1051/0004-6361/201526729
This paper supplies known periods and prior evidence about the uncertain candidate and unequal noise in time intervals.
- doi:10.1051/0004-6361/201833272
This paper provides later HARPS evidence for low significance near 200 days.
- usesdoi:10.1051/0004-6361/202348263
This paper describes the public HARPS-RVBank update and activity values.
- usesdoi:10.26093/cds/vizier.36830125
We use the corrected CDS table and preserve the exact 478-row target response from 21 October 2026.
- usesdoi:10.1051/0004-6361/201936686
This paper describes HARPS-RVBank radial velocities and night zero point corrections.
- usesdoi:10.1051/0004-6361/201833795
This paper gives the HARPS fibre-change time boundary used for separate offsets.
- usesA free BERV term removes over 99.9% of annual circular signal information at some phases in 151 HARPS designs under white noise sci:sha256:4f2be1c5e46742f40b4598bf5427841e077428f6d351fc726285900bc213d5ad
We use its general projection concept for a different nuisance term and target. We wrote new code and add measured velocities and residual-noise trials.
- supportsTwo activity models retain at least 93% of 197.8-day signal information in 261 HD 40307 HARPS nights sci:sha256:643e64d5676ed7a35429c8cd627d8dafed6d8634f52336276dbaa256f96e72ee
The conditional design result agrees with this earlier HD 40307 study. That result is not new here. Our data and weights differ. Our added results are residual-noise sensitivity trials, calibrated time tests, and a DRS mask audit.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- Combined TESS data recover 95.3 to 100% of added circular transits from planets of 1.5 to 2.5 Earth radii on a fixed HD 40307 g grid
A prior signed SCI study tested conditional sensitivity to added HD 40307 g radial velocity signals. Our flux test uses separate code and data.
- A 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
Our blind search of HD 40307 finds the 4.31, 9.62, 20.42 and 51.85-day planets. It does not detect the 197.8-day signal (K = 0.95 m/s, S = 14.7) at FAP < 0.1 %.
- usesA fixed Gaussian HARPS model gives a nominal 95% amplitude bound below 0.90 m/s at 197.8 days for HD 40307 orbits with eccentricity up to 0.60
We reuse its input data records, MIT night-mean preparation code, primary mean model, and four fitted signal periods. Its circular injection result defines the gap tested here. We add eccentric-orbit confidence sets and a bound for continuous eccentricity and phase.