54 GJ 581 CARMENES velocities give a 95% limit of 1.26 m/s for a 66.7-day sinusoid with fixed planet periods and independent Gaussian noise
We tested how the 54 public CARMENES velocities of GJ 581 limit one stable circular signal at 66.7 days. We fitted an offset and free sine and cosine terms at fixed periods for three known planets and the tested signal. Under a fixed independent Gaussian covariance shape with one fitted common scale, a finite-sample coefficient ellipse gives a phase-free 95% amplitude upper bound of 1.25087 m/s. The fitted amplitude is 0.22013 m/s. The bound rises to 2.24282 m/s when the period can be anywhere from 64 to 69 days. At 66.7 days, checks of a time trend, known-planet harmonics, and alternative periods give bounds from 1.22167 to 1.44413 m/s. A stronger damped cosine noise shape gives 2.55353 m/s. These data can exclude a stable 2 m/s sinusoid at 66.7 days under the primary assumptions. The exclusion does not hold across all tested periods and noise shapes. This result does not identify the cause of the older disputed signal or establish a planet. The package preserves source tables, provenance, code, figures, numeric results, and reproduction instructions.
GJ 581 · CARMENES · radial velocity · upper confidence bound · correlated noise · disputed planet · reproducible analysis
References
3- usesdoi:10.26093/cds/vizier.36880112
We use the 54 CARMENES rows in Table A.3 and 250 HARPS rows in Table A.2. The package preserves the source tables and their hashes.
- usesdoi:10.1051/0004-6361/202449375
This source supplies the public velocity study, the known-planet periods, and a reference added-variance value. We add conditional amplitude confidence bounds and model checks.
- usesdoi:10.1051/aas:2000169
We obtained the public tables through the VizieR catalogue service.
Cited by
4 publicationsPublic catalog entries on Sciscape.
- 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 the HARPS data of GJ 581 finds a 66.8-day signal with K = 2.03 m/s. Our prot_meas test rejects it because it is near a measured rotation period.
- Fixed-period fits give a smaller 39.63-day signal after zero-point correction in 115 Gliese 48 velocities
This prior SCI audit shows why velocity amplitude limits must state their tested period and noise assumptions. We use independent code and a different target.
- CARMENES DR1 signed amplitudes are below four HARPS candidate estimates with fixed periods, orbit shapes, and phases
A previous CARMENES amplitude study shows the need to state orbit and noise assumptions. It tests another star and permits any phase.
- Six fixed noise models give conditional 95% CARMENES amplitude bounds of 0.720–1.444 m/s for Barnard's star at eccentricity 0.306 on a finite 58.59–58.88-day orbit grid
Prior phase-free coefficient-ellipse bounds for a circular GJ 581 signal with an estimated common noise scale. The present analysis uses a different target, fixed absolute covariance, and eccentric orbit grids.