{"id":"471e2060-538f-4e28-ac36-49e28819ed16","arxiv_id":"2411.09506","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":6,"one_line_summary":"An 11.22-day, 2.78 Earth-mass planet candidate is reported around the nearby M dwarf Gl 725A, detected independently in SOPHIE optical and SPIRou infrared radial velocities.","lead":"Astronomers report a candidate super-Earth planet, Gl 725A b, orbiting one star of a nearby M dwarf binary system just 3.5 parsecs from Earth. The detection combines optical and infrared radial velocity measurements, giving a minimum mass of about 2.8 Earth masses.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The SPIRou 11.2 d detection rests on the Wapiti correction, which is not validated with injected signals; without this, the achromaticity argument and independent-detection claim are not secure.","rationale":"The paper is careful and thorough in many respects: the SOPHIE and SPIRou data are independently reduced, the activity indicators are examined, the GP modeling is detailed, the binary orbit is updated, and the TESS non-detection is quantified. The detection of a 1.67 m/s signal at 11.22 d in SOPHIE is plausible, and the joint Keplerian+GP model fits well. However, the claim that the signal is achromatic and therefore planetary hinges on the SPIRou detection being genuine. The SPIRou RVs are only usable after the Wapiti correction, a data-driven PCA that removes components correlated with BERV. The paper does not demonstrate that this correction preserves a small planet signal or does not create one. This is the weakest link: if Wapiti biases or injects the 11.2 d signal, the independent-detection argument collapses and the evidence reduces to SOPHIE alone, which is borderline significant. The reader's verdict of CONDITIONAL is appropriate; the missing injection test is a concrete, addressable requirement, not a fatal flaw. No independent confirmation or transit detection exists, so the planet remains a candidate. I therefore agree with the reader's assessment and see no reason to change the verdict.","tokens_in":46313,"tokens_out":7079,"duration_ms":65100,"concrete_test":"Inject a synthetic Keplerian signal with P=11.22 d and K=1.67 m/s (plus the observed long-term systematics) into the raw SPIRou per-line RV time series before applying Wapiti; run the identical Wapiti pipeline on 100 realizations with random planet phases and on a null set with no injected signal, then compare the recovered K and phase to the injected values and measure the false-positive rate at 11.2 d in the null set. If the recovered K is biased by >20% or the null set produces 11.2 d peaks with FAP<1% in >5% of realizations, the SPIRou detection cannot be validated. As a complementary check, re-derive SPIRou RVs with an independent telluric correction that does not use PCA (e.g., excluding telluric-contaminated lines or using a different telluric model) and test whether the 11.2 d signal persists.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim of an independent, achromatic detection of Gl 725A b requires that the 11.22 d signal in the SPIRou RVs is real and not an artifact of the Wapiti correction. The raw SPIRou RVs are dominated by a 174 d periodicity (close to the 180 d half-year BERV harmonic), and the 11.2 d signal appears only after Wapiti removes 7 principal components that are correlated with BERV and have periodicities of ~365, ~180, and ~90 d (Sect. 2.2.2). The paper provides no injection-recovery test to demonstrate that a small-amplitude (1.67 m/s) Keplerian signal at 11.22 d survives the Wapiti reconstruction with unbiased amplitude and phase. If the PCA components partially absorb the planet signal (because the observing cadence correlates with BERV) or if the correction introduces a spurious 11.2 d oscillation through the interaction of removed components with the window function, then the 'independent' SPIRou detection is spurious or biased. The SOPHIE detection alone has log(FAP) = -2.2 (~0.6%), which is significant but not overwhelming; the joint detection significance (log FAP = -5.4) and the achromaticity argument therefore rely heavily on the unvalidated SPIRou correction. The paper itself flags that residual NIR scatter could be 'residuals from the wapiti correction' (Sect. 7.3), but does not test its effect on the planet signal.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper reports the discovery of a super-Earth candidate, Gl 725A b, orbiting the M3V primary of a nearby (3.5 pc) binary system. The detection is based on radial velocities from SOPHIE in the optical and SPIRou in the near-infrared, with stellar activity modeled jointly by two Gaussian Processes (one per instrument) and a circular Keplerian. The best-fit parameters are P = 11.2201 ± 0.0051 d, K = 1.67 ± 0.20 m/s, and M_p sin i = 2.78 ± 0.35 M_Earth. The paper also presents an updated binary orbit, a TESS transit search with injection-recovery and TIP/FIP statistics, a non-detection of transits, and mass-radius inferred radii of 1.2–2.0 R_Earth.","tokens_in":46661,"tokens_out":10957,"duration_ms":99945,"significance":"If the detection holds, Gl 725A b would be one of the closest known super-Earths and a rare example of an S-type low-mass planet in an M dwarf binary, making it valuable for studies of planet formation in multiple systems. The paper has clear strengths: it uses two independent spectrographs in different wavelength regimes, applies several periodogram tools (GLS, l1, stacked BGLS), performs BIC-based model comparison, and includes extensive TESS work with both injection-recovery tests and TIP/FIP calculations. The analysis of the binary orbit from archival astrometry is also a useful contribution. However, the central claim of an independent, achromatic detection depends on the SPIRou Wapiti correction, which is not validated with injection-recovery tests in the current manuscript.","major_comments":[{"comment":"The SPIRou detection rests entirely on the Wapiti correction, but no injection-recovery validation is presented. The raw SPIRou RVs have their highest periodogram peak at 174 d, close to the half-year BERV harmonic, and the 11.2 d signal appears only after removing seven BERV-correlated principal components with periods of roughly 365, 180, and 90 d. Because the observing cadence is tied to seasonal visibility, the planet signal could in principle be partially absorbed by, or created through interaction with, the removed components. I request an injection-recovery test in which synthetic 1.67 m/s Keplerian signals at 11.22 d are injected into the raw per-line RVs and processed through the full Wapiti pipeline, with the recovered period, amplitude, and phase compared to input; a null test without an injected planet should also be run to ensure that the correction does not produce a spurious 11.2 d peak. This is load-bearing because the independent-detection and achromaticity claims depend on the SPIRou signal being real, and Sect. 7.3 itself concedes that residual NIR scatter may reflect Wapiti residuals.","section":"2.2.2, Fig. 3, 5.1, 7.3"},{"comment":"The independent-significance claim is stronger than the quoted false-alarm probabilities support. The SOPHIE GLS peak has log10(FAP) = -2.2 (about 0.6%), while the SPIRou post-Wapiti peak has log10(FAP) = -1.4 (about 4%), which is above the paper's own 1% FAP threshold used elsewhere (e.g., Fig. 1). The statement in Sect. 5.1 that 'Both data sets independently show a power excess' is technically true, but calling the SPIRou excess 'significant' is misleading. Please report a significance for the SPIRou Keplerian fit alone (e.g., via a likelihood-ratio test against a GP-only model) and, if that significance remains marginal, present the detection as SOPHIE-led with SPIRou as a consistency check rather than as an independent detection of comparable weight.","section":"2.1, 2.2, 5.1"},{"comment":"The TIP/FIP analysis reports TIP values of 0.7-0.8 for three transit epochs, but these are then dismissed as 'remaining systematics within the data' without a quantitative test. If the statistical method is a central part of the non-transit conclusion, those three epochs should be examined explicitly: e.g., by checking whether their times coincide with known spacecraft systematics, by including the PCA components in the noise model, or by showing that injecting a transit at the expected depth and duration yields higher TIP than the observed epochs. As written, the non-transit claim rests partly on an unexplained high-TIP discrepancy.","section":"6.3"}],"minor_comments":[{"comment":"There are six model columns but only four entries in the BIC and ΔBIC rows, and the values do not align unambiguously with the lnL values and sample sizes. Please clarify which BIC corresponds to which model and describe the null model explicitly.","section":"Table 3"},{"comment":"The caption refers to the MCMC routine described in Sect. 4.6, but the binary-orbit fit is described in Sect. 3.5.","section":"Fig. 6 caption"},{"comment":"The caption contains a typo: 'Details odf the wapiti correction' should read 'Details of the wapiti correction'.","section":"Fig. 3 caption"},{"comment":"Several identical BJD and RV entries are listed with different B_l values (e.g., BJD 2458592.100327, 2458593.111044, 2458768.746699, and 2459416.887505). If these are the four polarimetric sub-exposures, the text's statement that each entry is the binning of the four observations should be reconciled with the table; if they are duplicates, please remove them or explain.","section":"Table A.2"},{"comment":"There is a typo: 'compares them with with the reference HARPS sample' should read 'compares them with the reference HARPS sample'.","section":"3.1"}],"recommendation":"major_revision","confidential_remarks":"The Wapiti validation is the principal gate for this paper; without injection-recovery tests, the SPIRou detection is not independently established, and the current wording overstates the evidence. The target is scientifically important and the SOPHIE data alone may justify a candidate, but the manuscript needs either a rigorous Wapiti validation or a reframed, more cautious detection claim. The model-comparison table also needs correction before publication."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Short version: this is a careful, honest RV discovery paper for a nearby super-Earth candidate, and the central claim is plausible. The new things are the planet candidate itself and an updated 170-year binary orbit for Gl 725 that improves on Izmailov (2019). The analysis is well done: they find the 11.22 d signal in SOPHIE, check that it does not appear in activity indicators, model activity with two GPs, compare models with BIC, and run injection-recovery tests for other companions. The TESS transit search with TIP/FIP is also a step beyond the usual BLS search.\n\nThe soft spot is the SPIRou detection. The raw SPIRou RVs are dominated by a 174 d periodicity, close to the 180 d BERV harmonic, and the 11.2 d signal appears only after Wapiti removes seven PCA components correlated with BERV. The paper does not run an injection-recovery test to show that a 1.67 m/s Keplerian at 11.2 d survives Wapiti with unbiased amplitude and phase. That matters because SOPHIE alone has log(FAP) = -2.2 (~0.6% FAP), which is suggestive but not overwhelming. The joint detection (log FAP = -5.4) and the achromaticity argument lean on the unvalidated SPIRou correction. The authors are honest about this—they flag in Sect. 7.3 that residual NIR scatter might be \"residuals from the wapiti correction\"—but they do not test its effect on the planet signal.\n\nI don't think this is fatal. The SOPHIE detection is real and shows the right period; the Wapiti concern is addressable with injection tests, and the paper itself is appropriately cautious, calling the planet a candidate. The stellar rotation prior comes from published work, and the GP hyperparameters are fit, not forced. The binary orbit result is a useful side contribution.\n\nWho is this for? RV exoplanet people working on M dwarfs and anyone keeping track of the nearest planetary systems. It deserves a serious referee; the revision should require Wapiti injection-recovery tests or at least a clear discussion of how PCA could absorb or create an 11.2 d signal. I'd probably cite it as a candidate, with a caution flag.","headline":"A careful RV discovery paper for a nearby super-Earth candidate whose central claim is plausible, but the SPIRou detection rests on a data-driven correction that is not validated with injection tests.","tokens_in":47418,"tokens_out":2284,"would_cite":true,"duration_ms":20975,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"Gl 725A b is a candidate super-Earth in a binary system only 3.5 parsecs from Earth.","keywords":["M dwarf","radial velocity","super-Earth","stellar activity","Gaussian process","SOPHIE","SPIRou","binary system"],"falsifier":"Inject a synthetic 11.22-day Keplerian signal of known amplitude and phase into the raw SPIRou line-by-line velocities before running the Wapiti correction, and check whether the corrected series recovers the injected amplitude and phase; if the correction distorts or suppresses the signal, the infrared confirmation is not yet established. Alternatively, independent near-infrared radial velocities from another spectrograph at similar precision should reproduce K = 1.67 m/s at the same orbital phase.","tokens_in":46117,"feed_emoji":"🪐","tokens_out":3734,"duration_ms":34425,"temperature":0.7,"pith_summary":"The paper reports the discovery of a super-Earth candidate, Gl 725A b, orbiting the mid-M dwarf Gl 725A, which sits in a binary system just 3.5 pc away. The signal appears at an orbital period of 11.2201 ± 0.0051 days with a radial-velocity semi-amplitude of 1.67 ± 0.20 m/s in both SOPHIE optical data and SPIRou near-infrared data, implying a minimum mass of 2.78 ± 0.35 Earth masses. Because the signal is seen in two wavelength domains and is absent from stellar activity indicators, the authors argue it is achromatic and therefore planetary rather than activity-induced. If confirmed, the planet becomes one of the closest known exoplanets and joins a small group of low-mass S-type planets on short orbits around nearby M dwarfs.","feed_headline":"A super-Earth candidate found orbiting a star 3.5 parsecs away","feed_subtitle":"Optical and infrared radial velocities both show an 11.22-day, 2.78-Earth-mass companion around Gl 725A.","key_machinery":"Two independent Gaussian processes, one per instrument with shared rotation period and decay time, absorb quasi-periodic stellar activity while a circular Keplerian carries the 11.22-day signal. The near-infrared velocities require the Wapiti correction, a weighted-principal-component reconstruction that removes telluric and instrumental systematics correlated with the Earth's barycentric velocity, before the 11.22-day period becomes the strongest peak. The chromaticity argument is what separates planet from activity: spots imprint wavelength-dependent radial-velocity shifts, while a planet's Doppler signal is achromatic, so the agreement between optical and infrared amplitudes of about 1.6–1.7 m/s is the load-bearing evidence.","core_discovery":"The paper establishes that Gl 725A hosts a probable super-Earth with orbital period 11.2201 ± 0.0051 days and minimum mass Mp sin i = 2.78 ± 0.35 M⊕, detected independently in SOPHIE optical and SPIRou near-infrared radial velocities. The detection is made by fitting, for each instrument, a quasi-periodic Gaussian process for stellar activity together with a circular Keplerian; the planet parameters agree between instruments, and the 11.22-day signal is not found in any activity indicator. TESS photometry from 27 sectors shows no transit, and injection-recovery tests indicate the planet is likely non-transiting; mass-radius relations predict a radius near 1.4 Earth radii, placing it in the super-Earth regime.","pith_inferences":["If the Wapiti correction is what uncovers the 11.22-day signal, similar telluric-correction pipelines applied to other high-ecliptic-latitude M dwarfs could reveal additional low-amplitude planets currently hidden by telluric systematics.","The fitted binary inclination of 69.8 ± 0.4 degrees provides a prior for the planet's orbital inclination; if planet and binary are aligned, the true planet mass would be about 3.0 Earth masses, only slightly above the minimum.","A more direct test of the transit interpretation would be to model the unresolved Gl 725 A+B light curves with a forward binary model rather than a blended aperture, since the 21-arcsecond TESS pixels cannot separate the two stars cleanly.","Longer radial-velocity monitoring could establish whether the residual 111.9-day signal in the infrared data is stellar rotation or an additional companion, which would change the inferred architecture of the system."],"forward_implications":["Gl 725A b would be one of the closest known exoplanets, at 3.5 pc, making it a prime target for follow-up atmospheric and astrometric characterization if it can be confirmed.","The system adds an S-type planet around one component of a wide M-dwarf binary, supporting the view that low-mass planets can form and survive in binary systems with separations of tens of AU.","A minimum mass near 2.8 Earth masses with a predicted radius near 1.4 Earth radii places the planet in the super-Earth regime, informing planet-formation statistics around mid-M dwarfs.","The absence of transits in 27 TESS sectors, despite a predicted radius that would be detectable for nearly edge-on orbits, suggests a modest orbital inclination and implies the true mass is close to the reported minimum.","The detection demonstrates that sub-2 m/s planetary signals around M dwarfs are accessible with current optical and near-infrared spectrographs when stellar activity is modeled jointly."],"supporting_citations":[{"why":"Supplies the Wapiti method used to correct the SPIRou radial velocities for telluric and instrumental systematics, which is required before the 11.22-day signal becomes the dominant periodicity.","marker":"Ould-Elhkim et al. 2023"},{"why":"Provides the APERO data reduction software that extracts and calibrates the SPIRou spectra used for the near-infrared radial velocities.","marker":"Cook et al. 2022"},{"why":"Defines the line-by-line radial-velocity method applied to the SPIRou spectra, the basis for the infrared measurements.","marker":"Artigau et al. 2022"},{"why":"Supplies the l1 periodogram used to confirm that the 11.2-day peak is the strongest signal in the combined dataset and to reject aliases.","marker":"Hara et al. 2017"},{"why":"Provides the RadVel package used to fit the Keplerian and Gaussian-process models to the radial-velocity time series.","marker":"Fulton et al. 2018"},{"why":"Measures the stellar rotation period of 103.1 ± 6.1 days that sets the Gaussian process rotation-period prior and anchors the activity interpretation.","marker":"Donati et al. 2023"},{"why":"Provides the stellar mass, radius, and atmospheric parameters of Gl 725A used to convert the radial-velocity semi-amplitude into a minimum planetary mass.","marker":"Cristofari et al. 2022a"}],"fun_headline_variants":["Super-Earth candidate found just 3.5 parsecs from Earth","2.78-Earth-mass super-Earth candidate at 3.5 pc","Optical and infrared RVs confirm super-Earth at 3.5 pc","Nearby M dwarf hosts super-Earth candidate at 3.5 pc","Super-Earth detected by two spectrographs at 3.5 pc"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The planet interpretation rests on the belief that the 11.22-day signal is achromatic and therefore not due to stellar activity, together with the trust that the Wapiti correction of the infrared velocities neither creates nor removes a signal at that period, which the paper does not test with injected signals.","fun_headline_variants_meta":{"raw":{"variants":["Super-Earth candidate found just 3.5 parsecs from Earth","2.78-Earth-mass super-Earth candidate at 3.5 pc","Optical and infrared RVs confirm super-Earth at 3.5 pc","Nearby M dwarf hosts super-Earth candidate at 3.5 pc","Super-Earth detected by two spectrographs at 3.5 pc"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.001366,"raw_usage":{"total_tokens":5571,"prompt_tokens":1007,"completion_tokens":4564,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":623,"completion_tokens_details":{"reasoning_tokens":4461}},"tokens_in":623,"tokens_out":4564,"duration_ms":34244,"temperature":1.0,"reasoning_tokens":4461,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-12T20:33:34.905712+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Inject a synthetic 11.22-day Keplerian signal of known amplitude and phase into the raw SPIRou line-by-line velocities before running the Wapiti correction, and check whether the corrected series recovers the injected amplitude and phase; if the correction distorts or suppresses the signal, the infrared confirmation is not yet established. Alternatively, independent near-infrared radial velocities from another spectrograph at similar precision should reproduce K = 1.67 m/s at the same orbital phase.","supporting_citations":[{"cited_title":"F., et al","cited_arxiv_id":null,"evidence_quote":"Supplies the Wapiti method used to correct the SPIRou radial velocities for telluric and instrumental systematics, which is required before the 11.22-day signal becomes the dominant periodicity."},{"cited_title":"C., Boué, G., Laskar, J., & Correia, A","cited_arxiv_id":null,"evidence_quote":"Supplies the l1 periodogram used to confirm that the 11.2-day peak is the strongest signal in the combined dataset and to reject aliases."},{"cited_title":"F., Lehmann, L","cited_arxiv_id":null,"evidence_quote":"Measures the stellar rotation period of 103.1 ± 6.1 days that sets the Gaussian process rotation-period prior and anchors the activity interpretation."}],"review_version":1}