{"id":"f28894ca-7a70-4684-92a6-b3b32a416e0b","arxiv_id":"1908.01828","paper_version":2,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":6,"one_line_summary":"For six Type II-Plateau supernovae with confirmed progenitor detections, hydrodynamic modeling and direct imaging give consistent progenitor masses, contrary to earlier reports of a systematic offset.","lead":"This paper models the light curves and expansion velocities of six supernovae with confirmed progenitor stars to estimate the masses of the stars that exploded. It finds that these hydrodynamic mass estimates agree with masses from direct pre-explosion imaging, challenging a long-standing claim of a systematic discrepancy.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The sample is not fully 'secured': SN 2004et fails the paper's own disappearance-confirmation criterion, and it is the only clear mass outlier, so the central agreement claim depends on excluding an object that should not be in the sample.","rationale":"I read the paper as a transparent, well-structured re-analysis whose central claim is that hydrodynamic modelling does not systematically overestimate progenitor masses when the sample is restricted to SNe with confirmed progenitor identifications. The most load-bearing point is the definition of the sample itself. The inclusion of SN 2004et is in tension with the stated criterion that the progenitor must disappear in post-explosion images: Section 2.2 shows the original candidate did not disappear, and the replacement identification is an unconfirmed photometric excess. Since SN 2004et is also the only object whose Mhydro clearly exceeds the MpreSN range under both wind efficiencies, the conclusion is sensitive to this single inclusion. A second, intertwined sensitivity is the MZAMS-to-MpreSN conversion: the paper's own Figure 11 shows that with eta=1.0 two objects overproduce, while with eta=0.33 only SN 2004et does. Thus the strength of the agreement is not independent of the adopted mass-loss efficiency. I do not regard either issue as a reason to reject the paper; both are explicitly or implicitly acknowledged, and the paper's weaker claim that the hydrodynamic mass is 'not systematically larger' may survive a re-analysis. But the stronger claim of 'good agreement' for a sample of secured identifications is conditional. The reader's verdict of CONDITIONAL is appropriate; my concern sharpens the reason rather than changing the verdict.","tokens_in":25914,"tokens_out":8784,"duration_ms":91692,"concrete_test":"Remove SN 2004et from the analysis and re-plot Figure 11 for the remaining five SNe under both eta=1.0 and eta=0.33, explicitly giving the MpreSN range for SN 2012aw at eta=1.0 (MZAMS range 11-26 Msun from Table 2). If, with SN 2004et excluded and eta=1.0, SN 2012aw's Mhydro=23+1-2 Msun still exceeds the maximum MpreSN, then the central 'good agreement' claim depends on the reduced wind-efficiency choice even for the truly secured subsample; if no outliers remain under both eta values, the sample-integrity concern is resolved and the original conclusion stands.","verdict_should_be":"UNCHANGED","load_bearing_attack":"Section 2 lists as criterion (iii) that the progenitor identification be confirmed via its disappearance in post-explosion images. For SN 2004et, Section 2.2 reports that Crockett et al. (2011) found the original Li et al. candidate still present and resolved into at least three sources; the adopted progenitor is only an R/I-band flux excess with a tentative ZAMS mass of 8+5−1 Msun that the authors themselves say needs future confirmation. Thus SN 2004et does not meet the paper's own selection criterion, and Section 5.4's statement that 'all our objects have secured progenitor identifications' is contradicted. This matters because Figure 11 shows SN 2004et is the clearest outlier under both wind efficiencies: with eta=1.0 it lies above the MpreSN range together with SN 2012aw, and with eta=0.33 it is the only outlier. If the sample is reduced to the five objects that actually satisfy criterion (iii), the claimed 'good agreement' is being evaluated on a sample from which the one discrepant object was removed. Moreover, with eta=1.0 the remaining sample still has SN 2012aw above the MpreSN range, so even a five-object sample does not show agreement unless the reduced mass-loss rate is adopted. The conclusion is therefore conditional on two intertwined choices: excluding an object that fails the stated selection rule, and preferring eta=0.33 over eta=1.0 for the MESA mass-loss conversion.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper models the bolometric light curves and photospheric velocity evolution of six Type II-Plateau supernovae (SN 2004A, SN 2004et, SN 2005cs, SN 2008bk, SN 2012aw, and SN 2012ec) using the 1D Lagrangian hydrodynamic code of Bersten et al. (2011). The authors adopt double-polytropic pre-SN models, fix the progenitor radius to values from pre-explosion imaging where possible, and derive hydrodynamic masses Mhydro, explosion energies, and nickel masses. They then compare Mhydro with pre-SN masses MpreSN obtained by evolving the ZAMS mass ranges from direct progenitor detections with MESA stellar models under two wind-efficiency choices (eta=1.0 and eta=0.33). The central claim is that, contrary to previous literature, the hydrodynamic masses are not systematically larger than the masses derived from direct detections; the paper concludes that the two methods give good agreement for this sample.","tokens_in":26231,"tokens_out":3614,"duration_ms":37372,"significance":"If the central claim holds, the paper would provide an important counterexample to a widely discussed mass discrepancy between hydrodynamic modeling and direct progenitor detections for SNe II-P. The work has several strengths: it uses a published hydrodynamic code with a documented history, it models both light curves and photospheric velocities, it compares against multiple previous modeling efforts (Morozova et al. 2018; Pumo et al. 2017; Utrobin & Chugai 2008, 2009), it tests a stellar-evolution pre-SN model for SN 2008bk in Appendix A, and it gives explicit parameter ranges with a candid discussion that they are not statistical errors. The sample is small but deliberately selected for data quality, and the comparison with direct detections is a genuine empirical test. However, the strength of the conclusion is weakened by two intertwined issues: one object (SN 2004et) does not appear to meet the paper's own selection criterion, and the agreement depends on which wind efficiency is adopted in the MESA conversions.","major_comments":[{"comment":"SN 2004et does not satisfy the paper's stated selection criterion (iii). Section 2.2 reports that Crockett et al. (2011) found the original Li et al. candidate still visible after the SN faded and resolved into at least three sources, with the progenitor detected only as an excess of R- and I-band flux and a tentative ZAMS mass of 8+5-1 Msun that the authors say still needs confirmation. This directly contradicts the statement in Section 5.4 that 'all our objects have secured progenitor identifications.' The issue is load-bearing because Figure 11 shows SN 2004et is the clearest outlier under both wind efficiencies: under eta=1.0 it lies above the MpreSN range together with SN 2012aw, and under eta=0.33 it is the only object that does so. The authors should either present additional evidence that justifies keeping SN 2004et in the sample or repeat the comparison on the five objects that actually meet criterion (iii), reporting the outcome for both eta values.","section":"Section 2.2 and Section 5.4"},{"comment":"The 'good agreement' conclusion is not robust to the adopted wind efficiency in the MESA mass-loss prescription. With eta=1.0, two objects (SN 2004et and SN 2012aw) have hydrodynamic masses above the pre-SN mass ranges, while with eta=0.33 the overestimate remains only for SN 2004et. Section 5.4 itself states that mass-loss rates are uncertain by a factor of two to ten, so the choice eta=0.33 is not uniquely forced by the quoted literature. Since the entire mass-discrepancy verdict depends on this choice, the paper needs either a principled argument for why eta=0.33 is the physically appropriate value for these RSG progenitors, or an explicit sensitivity statement showing how the number of discrepant objects changes as eta is varied within the stated uncertainty range.","section":"Section 5.4 and Figure 11"},{"comment":"The quantitative basis of the comparison is limited by the model-selection procedure and by parameter adjustments that are not part of the direct-detection constraints. The paper states in Section 4 that the preferred models were chosen by visual comparison and that the ranges in Table 3 are not statistical errors. In addition, for SNe 2004A, 2008bk, and 2012ec the explosion epoch was adjusted based on the modelling, and for SNe 2004A and 2004et the progenitor radius was set to values outside the ranges listed in Table 2. These adjustments are described as necessary to fit the observations, but their covariance with Mhydro is not quantified. Because the claim is that the two mass-determination methods agree, the authors should show, at least for the discrepant objects, that the conclusion is unchanged when the literature radius or explosion epoch is used, or provide a justification for why the adjusted values should be preferred.","section":"Section 4 and Table 3"}],"minor_comments":[{"comment":"The abstract and Section 2 state that all six objects satisfy criterion (iii), but Section 2.2 shows that SN 2004et does not; the wording should be corrected or the criterion relaxed and the sample description revised accordingly.","section":"Abstract and Section 2"},{"comment":"The dashed line for the CSM model of SN 2004et is described in the text as improving the early light curve, but the figure caption does not define the dashed line; please add a legend or caption note for clarity.","section":"Section 4, Figure 3"},{"comment":"The comparison with previous hydrodynamic modeling results in Table 5 would be easier to interpret if the table included the explosion energies and radii from those works, since the degeneracy between Mhydro, R, and E is a central theme of the paper.","section":"Section 5.3 and Table 5"}],"recommendation":"major_revision","confidential_remarks":"The paper addresses a timely and contested question and contains a credible modeling effort, but the central claim currently rests on a sample that includes an object failing the authors' own selection criterion and on a wind-efficiency choice that is not robustly justified. These are fixable within the manuscript's scope: the authors can re-run or re-present the comparison for the five-object sample, and they can add a sensitivity analysis for eta. I would encourage the editor to send a revised version back to the same referee."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The paper re-derives physical parameters for six well-observed SNe II-P with a published hydrodynamic code, then compares the hydrodynamic masses against pre-SN masses from MESA tracks. The stated conclusion is that the long-discussed mass discrepancy disappears once you restrict to objects with confirmed progenitor identifications. That conclusion is more conditional than the abstract admits, and the paper's own text gives you the tools to see why.\n\nWhat it does well: the modeling is careful, the paper is refreshingly honest about the degeneracies, the informal error bars, and the places where it had to tune inputs. The comparison with the LN85 scaling relations is a useful cautionary tale, and the appendix on model sensitivity is worth reading. If you work on SNe II-P progenitor masses, this is a legitimate touchstone.\n\nNow the soft spots. The sample is supposed to satisfy criterion (iii): post-explosion confirmation of the progenitor's disappearance. But Section 2.2 says SN 2004et fails exactly that — the original candidate was resolved into three sources, and the adopted progenitor is just an R/I-band flux excess with a tentative ZAMS mass that the authors themselves say needs future confirmation. Yet Section 5.4 states that \"all our objects have secured progenitor identifications.\" That sentence is contradicted by their own earlier account. And it matters: under the preferred eta=0.33 wind efficiency, SN 2004et is the only object sitting above the pre-SN mass range. Under eta=1.0, SN 2012aw joins it. So the central agreement effectively depends on two intertwined choices: keeping an object that doesn't meet the stated selection rule, and preferring the lower mass-loss rate despite the acknowledged factor-of-two-to-ten uncertainty in wind rates. The paper shows the eta dependence, which is honest, but the conclusion should have been framed as \"consistent for five objects under a reduced wind efficiency,\" not as a clean resolution.\n\nThe other adjustments — three explosion epochs shifted to fit the models, radii for 2004A and 2004et raised above the literature ranges — are acknowledged and are minor compared to the sample-selection issue. The explosion epoch for 2004A is outside the literature error bars, but they admit it and give a justification.\n\nWho gets value from this: anyone modeling SNe II-P light curves, and anyone who uses LN85 without checking it. It deserves a serious referee — the central question is real and the paper is well-executed, but the referee should push on the contradiction between the selection criterion and the inclusion of 2004et, and ask for a conclusion that is accurately scoped to what the five-object sample plus the chosen wind efficiency actually shows. I would send it out.","headline":"A transparent re-analysis that undercuts its own central claim: the one object that fails the paper's 'secured progenitor' criterion is the only outlier under the preferred mass-loss calibration.","tokens_in":26786,"tokens_out":2548,"would_cite":true,"duration_ms":29267,"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":"Hydrodynamic modelling of six well-observed SNe II-P yields progenitor masses in agreement with direct detections, not the systematic overestimate previously reported.","keywords":["Type II-Plateau supernovae","supernova progenitors","red supergiants","hydrodynamic modelling","light curves","stellar mass loss","mass discrepancy","explosion energy"],"falsifier":"Measure the actual mass-loss rates of nearby red supergiants comparable to these progenitors using multi-epoch high-resolution spectroscopy at optical and infrared wavelengths; if the measured rates are close to the standard unclumped values rather than a factor of three lower, the reduced-efficiency comparison that produces the claimed agreement would fail, and the hydrodynamic masses would again sit above the direct estimates for SN 2012aw and SN 2004et.","tokens_in":25657,"feed_emoji":"💥","tokens_out":10697,"duration_ms":104071,"temperature":0.7,"pith_summary":"Type II-Plateau supernovae—exploding red supergiants whose light stays near a plateau for roughly a hundred days—are common, but earlier studies found that masses inferred from explosion modelling came out systematically larger than masses derived from direct images of the progenitor star. This paper tests that claimed discrepancy on the six objects with the strongest evidence: well-sampled light curves and velocities, a directly detected progenitor, and confirmation that the detected star disappeared after the explosion. It models each explosion hydrodynamically with the progenitor radius fixed to the range from pre-explosion photometry, obtaining pre-supernova masses between 10 and 23 $M_\\odot$, energies between 0.2 and 1.4 foe ($1\\ \\mathrm{foe}=10^{51}$ erg), and $^{56}$Ni masses between 0.0015 and 0.085 $M_\\odot$. When the direct-detection masses are converted into pre-supernova masses with stellar-evolution models, the hydrodynamic masses are not systematically larger: with a reduced wind mass-loss efficiency only SN 2004et overestimates, and that object's progenitor identification is itself uncertain. The paper concludes that the long-reported mass discrepancy is not an intrinsic failure of hydrodynamic modelling, and that simple analytic scaling relations in common use give unreliable masses and radii.","feed_headline":"Six supernovae: model masses match direct progenitor detections","feed_subtitle":"A reanalysis with secure identifications and reduced wind loss finds no systematic overestimate, contradicting earlier studies.","key_machinery":"The central machinery is a one-dimensional Lagrangian radiation-hydrodynamics code that simulates the explosion and predicts bolometric light curves and photospheric velocities. The pre-supernova structures are double-polytropic models—hydrostatic configurations built from a dense core plus an extended hydrogen-rich envelope—so that mass and radius can be treated independently; fixing the radius to the values from pre-explosion photometry breaks the mass–radius–energy degeneracy. The remaining free parameters (pre-supernova mass, explosion energy, and $^{56}$Ni mass) are adjusted until the light curve and velocity evolution match. The second load-bearing component is the conversion of directly detected zero-age main-sequence masses into pre-supernova masses using stellar-evolution calculations with a wind mass-loss prescription, evaluated at two wind efficiencies ($\\eta = 1.0$ and $0.33$); the lower value is motivated by the factor of two to ten uncertainty in mass-loss rates. The radiative-transfer treatment also includes a minimum opacity floor to compensate for opacities underestimated under local thermodynamic equilibrium in rapidly expanding, non-thermally ionised ejecta.","core_discovery":"On the paper's own terms, the central claim is that for six SNe II-P (SN 2004A, SN 2004et, SN 2005cs, SN 2008bk, SN 2012aw, and SN 2012ec) hydrodynamic modelling of bolometric light curves together with Fe ii 5169 Å photospheric velocities can reproduce the observations with pre-supernova masses that agree with the masses from direct progenitor detections. Since the detected-star masses are zero-age main-sequence values while the hydrodynamic masses are pre-explosion values, the comparison needs a mass-loss calculation in between; using the standard wind prescription causes two of the six models to overestimate, whereas reducing the wind efficiency to one third—justified by evidence that computed mass-loss rates are too high by factors of two to ten—leaves only SN 2004et discrepant, an object whose progenitor identification is not secure. This is offered as evidence against the systematic offset claimed in earlier hydrodynamical studies, and the paper also finds a strong mass–explosion-energy correlation (correlation coefficient $\\rho = 0.91$) and shows that the widely used 1980s analytic scaling relations overestimate ejected mass and underestimate radius for this sample.","pith_inferences":["Beyond the paper: if the factor-of-three reduction in wind mass-loss rates is independently confirmed, then the historical II-P mass discrepancy may be best described as a calibration artifact of stellar winds, and direct-imaging and hydrodynamic masses can be treated as mutually validating measurements.","Beyond the paper: the need for radii above the photometric range in SNe 2004A and 2004et suggests that bolometric-correction radii for dusty or crowded red-supergiant environments could be systematically low; this is testable with resolved multi-band imaging of other nearby red supergiants.","Beyond the paper: a calibrated mass–explosion-energy correlation derived from a larger set of modelled II-P could be used to estimate progenitor masses for distant II-P where no progenitor is detected, effectively turning light-curve modelling into a population-level mass estimator."],"forward_implications":["For each of the six best-observed II-P supernovae there exists a hydrodynamic model that satisfies the light curve, the velocity evolution, and the directly measured progenitor radius and mass, so the previously claimed systematic disagreement is not forced by the observations.","The deciding layer is stellar mass loss, not explosion physics: with standard wind rates two objects disagree (SN 2004et and SN 2012aw), while with the reduced rate only the uncertain-identification object SN 2004et remains discrepant.","Simple analytic relations that estimate mass, radius, and energy from a few plateau observables are not reliable for this sample: they overestimate ejected mass by about a factor of 1.75 and underestimate pre-supernova radius by about a factor of 3.3.","Progenitor mass and explosion energy are strongly correlated (correlation coefficient $\\rho = 0.91$), and correlations involving nickel mass tighten once SN 2004A's uncertain explosion epoch is set aside."],"supporting_citations":[{"why":"Supplies the one-dimensional Lagrangian radiation-hydrodynamics code used to compute the bolometric light curves and photospheric velocities.","marker":"Bersten et al. (2011)"},{"why":"States the prior claim that hydrodynamic masses are systematically larger than pre-explosion-image masses, the baseline this paper tests.","marker":"Utrobin & Chugai (2008)"},{"why":"Provides photometry for SN 2004et and is one of the earlier studies reporting the mass discrepancy.","marker":"Maguire et al. (2010)"},{"why":"Previous hydrodynamic modelling of several objects in the sample; its light-curve-only fitting and lower masses are the direct comparison for method and results.","marker":"Morozova et al. (2018)"},{"why":"Reanalysis of the systematic errors in converting pre-explosion photometry to initial mass, which broadens the direct-detection mass and radius ranges used for the comparison.","marker":"Davies & Beasor (2018)"},{"why":"Confirms the disappearance of the progenitor candidates for several sample supernovae, satisfying the selection criterion of secured identifications.","marker":"Maund et al. (2014a)"},{"why":"One of the wind mass-loss prescriptions combined into the Dutch scheme used to convert initial masses into pre-supernova masses.","marker":"de Jager et al. (1988)"},{"why":"Line-driven wind mass-loss rates that set the standard efficiency value (eta = 1.0) in the mass-loss prescription.","marker":"Vink et al. (2001)"},{"why":"Argues that standard mass-loss rates are overestimated by about a factor of three, the motivation for testing eta = 0.33.","marker":"Puls et al. (2008)"},{"why":"Reviews clumping and overestimated stellar wind mass-loss, providing further basis for the reduced wind efficiency choice.","marker":"Smith (2014)"}],"fun_headline_variants":["SNe II-P masses: models and direct detections align","Reanalysis finds no systematic mass offset in six Type II-P supernovae","Hydrodynamic and direct masses agree for six SNe II-P with tuned wind loss","Mass discrepancy in SNe II-P resolved by recalibrated mass loss","Six supernovae: no mass discrepancy after wind-loss revision"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The comparison assumes the stellar wind mass-loss rates used to convert directly measured initial masses into pre-supernova masses are known well enough; if the true rates are close to the standard high values rather than the reduced value used here, the agreement for SN 2012aw disappears and for SN 2004et worsens.","fun_headline_variants_meta":{"raw":{"variants":["SNe II-P masses: models and direct detections align","Reanalysis finds no systematic mass offset in six Type II-P supernovae","Hydrodynamic and direct masses agree for six SNe II-P with tuned wind loss","Mass discrepancy in SNe II-P resolved by recalibrated mass loss","Six supernovae: no mass discrepancy after wind-loss revision"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.001006,"raw_usage":{"total_tokens":4314,"prompt_tokens":1069,"completion_tokens":3245,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":685,"completion_tokens_details":{"reasoning_tokens":3150}},"tokens_in":685,"tokens_out":3245,"duration_ms":21856,"temperature":1.0,"reasoning_tokens":3150,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-14T15:01:53.020109+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure the actual mass-loss rates of nearby red supergiants comparable to these progenitors using multi-epoch high-resolution spectroscopy at optical and infrared wavelengths; if the measured rates are close to the standard unclumped values rather than a factor of three lower, the reduced-efficiency comparison that produces the claimed agreement would fail, and the hydrodynamic masses would again sit above the direct estimates for SN 2012aw and SN 2004et.","supporting_citations":[{"cited_title":"P., & Chugai, N","cited_arxiv_id":null,"evidence_quote":"States the prior claim that hydrodynamic masses are systematically larger than pre-explosion-image masses, the baseline this paper tests."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Provides photometry for SN 2004et and is one of the earlier studies reporting the mass discrepancy."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Previous hydrodynamic modelling of several objects in the sample; its light-curve-only fitting and lower masses are the direct comparison for method and results."}],"review_version":1}