{"id":"14cfeb9d-f2c7-4b1a-b470-0e917c3a84f3","arxiv_id":"2607.04594","paper_version":1,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":4.0,"correctness_risk":"low","formal_verification":"none","parameter_count":3,"one_line_summary":"Four microlensing events yield cold giant planets of ~0.2–2.5 MJ around ~0.07–0.6 M⊙ hosts at ~0.7–6 au, all consistent with Galactic bulge lenses.","lead":"Four cold giant planets were found via high-cadence microlensing light-curve anomalies and Bayesian mass inference. The sample expands the census of giant planets beyond the snow line around low-mass bulge stars.","discovery_kind":"extension","skeptic_critique":{"model":"grok-4.5","headline":"No significant objection identified beyond the reader's already-flagged Galactic prior.","rationale":"The reader's weakest_assumption correctly isolates the single load-bearing external input: the Jung et al. Galactic prior used to convert (tE, θE) into physical parameters. All other steps (photometric reduction, 2L1S modeling, degeneracy checks, source characterization via RGC, θE = θ*/ρ) are standard, transparent, and internally consistent. Because the mass ratios themselves are model-independent and of order 10^{-3}, and the projected separations remain of order a few au even under large prior shifts, the qualitative classification as cold giant planets is secure. The CONDITIONAL verdict already accounts for the missing public photometry/code and the one event without a secure θE; no stronger concern emerges that would justify moving to REJECT or to unconditional ACCEPT. The recommended concrete test simply quantifies the prior sensitivity already flagged by the reader.","tokens_in":18853,"tokens_out":588,"duration_ms":5238,"concrete_test":"Re-run the Bayesian posteriors of Table 6 for all four events under two alternate priors (e.g., the Koshimoto et al. 2021 Galactic model and a pure power-law mass function with α=1.3 vs. 2.0). If any median Mp falls below ~0.1 MJ or any a⊥ falls well inside the host snow line, the strongest claim weakens; otherwise the claim is robust to the known prior uncertainty.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper's central claim (four companions are cold giant planets with Mh ~0.07–0.6 M⊙, Mp ~0.2–2.5 MJ, a⊥ ~0.7–6 au, DL ~6.6–7.9 kpc) rests on (i) secure 2L1S mass ratios q~10^{-3} from light-curve modeling and (ii) Bayesian conversion of measured (tE, θE) via the Jung et al. (2021, 2022) Galactic model and mass function (Section 5, Eqs. 3–5). The modeling is careful: degeneracies (inner–outer, close–wide, accidental) are quantified, 1L2S alternatives are tested and disfavored where relevant, and finite-source ρ is measured for three of four events. The only material soft spot is precisely the one the reader already identified—the prior. Reasonable variations of that prior can shift absolute masses and distances by tens of percent, but do not move the companions out of the giant-planet regime or inside the snow line for the reported q and s values. No internal inconsistency, circular derivation, or unexamined degeneracy that would overturn the claim is present.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The paper reports four cold giant planets discovered in high-cadence microlensing events OGLE-2016-BLG-0261, KMT-2025-BLG-0026, KMT-2025-BLG-0030, and KMT-2025-BLG-2272. Short-duration anomalies are modeled as 2L1S systems with mass ratios q ~ 10^{-3}. Finite-source effects yield angular Einstein radii for three events. Bayesian analysis using measured t_E and θ_E (with the Jung et al. 2021/2022 Galactic model and mass function) produces host masses ~0.07–0.6 M_⊙, companion masses ~0.2–2.5 M_J, projected separations ~0.7–6 au (at or beyond the snow line), and distances ~6.6–7.9 kpc consistent with bulge lenses. Degeneracies (inner–outer, close–wide, accidental) and 1L2S alternatives are quantified and discussed.","tokens_in":19145,"tokens_out":1173,"duration_ms":10333,"significance":"The work expands the homogeneous sample of cold giant planets from high-cadence surveys (KMTNet, OGLE, PRIME) and supplies additional empirical constraints on giant-planet occurrence around low-mass hosts beyond the snow line. The light-curve modeling is careful: grid searches, explicit treatment of known degeneracies, 1L2S tests where relevant, and secure ρ measurements for three of four events. Physical parameters rest on standard Bayesian conversion of independently measured (t_E, θ_E). The results are useful for demographic studies even if absolute masses shift modestly under prior variations, because the companions remain in the giant-planet regime for the reported q and s.","major_comments":[{"comment":"Section 5 and Table 6: For KMT-2025-BLG-0026 the close and wide solutions have substantially different q (4.62e-3 vs 0.50e-3) and ρ, yet only the close solution is used for the adopted θ_E and the primary physical-parameter summary. Although Δχ^{2} = 16.6 favors the close solution, the wide solution still yields a giant-planet mass (and a larger a_⊥). The paper should either present both posteriors side-by-side in the main text/table or quantify how the choice affects the claimed mass and separation ranges, so that the central claim does not rest solely on one branch of an accidental degeneracy.","section":null},{"comment":"Section 5, Eqs. (3)–(5) and the weakest-assumption note: Absolute host and planet masses (and DL) depend on the Jung et al. (2021, 2022) Galactic density, kinematics, and mass-function prior. Reasonable variations of that prior can shift masses and distances by tens of percent. While the companions remain giant planets for the measured q, the paper should briefly test or cite the sensitivity of the reported medians and 1σ intervals to alternative standard priors (e.g., different disk/bulge mass functions or density profiles) so that the numerical ranges quoted in the abstract and Table 6 are not over-interpreted as prior-independent.","section":null}],"minor_comments":[{"comment":"Title page and abstract: Event naming is inconsistent (KMT-2016-BLG-1679 vs OGLE-2016-BLG-0261). Table 1 clarifies the correspondence, but the abstract and early text should use a single primary designation consistently.","section":null},{"comment":"Table 3 and Table 4: HJD' zero-points differ between events (HJD-2450000 vs HJD-2460000). A single clarifying note in each table caption would prevent misreading of t0 values.","section":null},{"comment":"Figure 5 and Section 4: For the two faint sources whose colors are taken from HST CMD alignment, a short quantitative statement of the color uncertainty (beyond the tabulated ± values) would strengthen the θ_* error budget.","section":null},{"comment":"Section 3.2: The accidental (not classical close–wide) nature of the KMT-2025-BLG-0026 degeneracy is correctly identified; a one-sentence cross-reference to the analytic s† relation used for the other events would make the distinction even clearer.","section":null},{"comment":"Scattered typographical issues (e.g., \"Microle nsing\", \"F our\", \"OBSER V ATIONS\", missing spaces in author lists) should be cleaned in production.","section":null}],"recommendation":"minor_revision","confidential_remarks":"The manuscript is a solid, incremental contribution of the type routinely published in this field. The only load-bearing soft spots are the prior dependence of the Bayesian masses and the handling of the accidental degeneracy for one event; both are addressable with modest additional text or a short sensitivity test. No evidence of circularity or unexamined modeling failure. Suitable for the journal after minor revision."},"author_rebuttal":null,"desk_editor":{"model":"grok-4.5","letter":"These are four new cold giant planets (OGLE-2016-BLG-0261Lb and three 2025 KMT events) with q ~ 10^{-3}, projected separations 0.7–6 au, and Bayesian host/planet masses that put them firmly in the giant-planet regime around low-mass hosts. That is the actual news: concrete new systems that enlarge the homogeneous high-cadence sample used for occurrence-rate work.\n\nThe analysis is done the way the community expects. Grid searches over (s, q, α), full re-optimization, explicit treatment of inner–outer, close–wide, and one accidental degeneracy, 1L2S tests where the anomaly is a short positive bump, and secure finite-source ρ for three of the four events. Error-bar rescaling is standard. Source colors and θ* follow the usual RGC + HST alignment + Kervella route. The Bayesian step (Jung et al. 2021/2022 Galactic model + mass function) is transparent and correctly weights the measured tE and θE; it is not circular.\n\nSoft spots are real but limited. Absolute masses and distances move with the Galactic prior; tens-of-percent shifts are possible, yet the companions stay giant planets beyond the snow line for the measured q and s. One event has only an upper limit on ρ, so its θE is a lower bound. Photometry and modeling code are not public yet. None of these overturn the detections or the basic physical picture.\n\nThis is for people who build or use the microlensing planet sample—occurrence papers, snow-line demographics, low-mass-host statistics. It is not a methods paper and does not claim to be. A serious editor should send it to referees; the modeling is careful enough and the systems are new enough to deserve that time. I would cite the four systems when I next update a cold-planet census.","headline":"Four new cold giants from the standard high-cadence pipeline; careful modeling, prior-dependent masses, solid incremental addition to the homogeneous sample.","tokens_in":20093,"tokens_out":489,"would_cite":true,"duration_ms":5562,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.5","headline":"High-cadence microlensing surveys have found four cold giant planets orbiting low-mass stars beyond their snow lines.","keywords":["gravitational microlensing","exoplanet detection","cold giant planets","high-cadence surveys","binary-lens modeling","angular Einstein radius","Bayesian mass estimation","snow line"],"falsifier":"High-resolution imaging years after the events that measures the lens flux and the lens–source relative proper motion; if those measurements force host masses or distances outside the reported Bayesian posteriors (or resolve the close–wide or inner–outer degeneracies in a way that contradicts the adopted solutions), the physical parameters claimed here would be ruled out.","tokens_in":19757,"feed_emoji":"🪐","tokens_out":734,"duration_ms":5082,"temperature":0.7,"pith_summary":"This paper reports four new giant planets found by watching short anomalies in high-cadence microlensing light curves from the KMTNet, OGLE, and PRIME surveys. Binary-lens models with mass ratios of order 10^{-3} fit the anomalies, and finite-source effects measured for three events yield the angular Einstein radius. A Bayesian analysis that folds in the event timescales and Einstein radii then converts those observables into physical parameters: hosts of roughly 0.07–0.6 solar masses, planets of 0.2–2.5 Jupiter masses, projected separations of 0.7–6 au (at or beyond the snow line), and distances of 6.6–7.9 kpc consistent with Galactic-bulge lenses. The detections enlarge the homogeneous sample of cold giants around low-mass stars that only microlensing can systematically reach, thereby tightening empirical constraints on how efficiently giant planets form beyond the snow line.","feed_headline":"Four cold giant planets found beyond the snow line","feed_subtitle":"Microlensing of low-mass stars yields 0.2–2.5 Jupiter-mass companions at 0.7–6 au in the Galactic bulge","key_machinery":"Binary-lens single-source (2L1S) light-curve modeling that recovers the mass ratio q and normalized source radius ρ, followed by Bayesian conversion of the measured Einstein timescale t_E and angular Einstein radius θ_E = θ_*/ρ into host and planet masses and distances via a Galactic density–kinematics–mass-function prior.","core_discovery":"Four microlensing events (OGLE-2016-BLG-0261, KMT-2025-BLG-0026, KMT-2025-BLG-0030, KMT-2025-BLG-2272) each show a short-duration anomaly that is well described by a binary-lens single-source model with planet-to-host mass ratio q ~ 10^{-3}. Secure finite-source measurements in three events give the angular Einstein radius; a Bayesian analysis of the measured timescales and Einstein radii then yields host masses ~0.07–0.6 M_⊙, companion masses ~0.2–2.5 M_J, projected separations ~0.7–6 au, and distances ~6.6–7.9 kpc, confirming that all four companions are cold giant planets orbiting low-mass hosts at or beyond the snow line and consistent with bulge lenses.","pith_inferences":[],"forward_implications":[],"fun_headline_variants":["Four cold giant planets found beyond snow lines by microlensing","Microlensing detects four cold giants around low-mass bulge hosts","High-cadence surveys yield four cold planets at 0.7–6 au","Four 0.2–2.5 MJ cold giants orbiting low-mass stars past snow lines","Cold giant planets beyond snow lines: four new microlensing finds"],"cache_read_input_tokens":16512,"weakest_assumption_plain":"The adopted Galactic model for disk and bulge densities, kinematics, and the stellar mass function correctly supplies the prior probabilities that turn the measured event timescales and Einstein radii into host and planet masses.","fun_headline_variants_meta":{"raw":{"variants":["Four cold giant planets found beyond snow lines by microlensing","Microlensing detects four cold giants around low-mass bulge hosts","High-cadence surveys yield four cold planets at 0.7–6 au","Four 0.2–2.5 MJ cold giants orbiting low-mass stars past snow lines","Cold giant planets beyond snow lines: four new microlensing finds"]},"model":"grok-4.5","effort":"low","cost_usd":0.00555,"raw_usage":{"total_tokens":1599,"prompt_tokens":963,"num_sources_used":0,"completion_tokens":102,"cost_in_usd_ticks":55500000,"prompt_tokens_details":{"text_tokens":963,"audio_tokens":0,"image_tokens":0,"cached_tokens":128},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":534,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":963,"tokens_out":102,"duration_ms":4000,"temperature":1.0,"reasoning_tokens":534,"cache_read_input_tokens":128,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-11T16:42:46.696150+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"High-resolution imaging years after the events that measures the lens flux and the lens–source relative proper motion; if those measurements force host masses or distances outside the reported Bayesian posteriors (or resolve the close–wide or inner–outer degeneracies in a way that contradicts the adopted solutions), the physical parameters claimed here would be ruled out.","supporting_citations":[],"review_version":1}