Secular Light Curve of Exocomet 3I/ATLAS, and its Location on a Comet Evolutionary Diagram

Referee: The definition of Mass-Loss Age as the inverse of total mass loss (aggregated from 97 papers) is introduced without derivation, citation of a correlation to dynamical age, or validation against solar-system Oort comets with known return counts. This proxy directly supplies the horizontal coordinate of the CED and is therefore load-bearing for the Oort classification and extrasolar conclusion.

Authors: We acknowledge that the Mass-Loss Age is presented as a new proxy without an explicit derivation or prior citations in the submitted draft. It rests on the physical reasoning that cumulative mass loss reflects the degree of evolutionary processing, with the inverse serving as a relative age indicator. In the revised manuscript we will add a short explanatory paragraph deriving the proxy from first principles of mass-loss driven fading, cite supporting literature on mass loss as an evolutionary clock for comets, and note consistency with the low dynamical age implied by the comet's interstellar origin. While a full statistical validation against the return counts of all known solar-system Oort-cloud comets lies outside the scope of this work, the resulting value of 0.16 comet years places 3I in the expected region for dynamically young objects, supporting the Oort-cloud classification without overclaiming. revision: partial

Referee: No error propagation or uncertainty estimates are provided for the summed production rates drawn from the 97 papers, rendering the numerical value Mass-Loss Age = 0.16 comet years insufficiently constrained for quantitative placement on the CED.

Authors: We agree that quantitative uncertainties are required for robust placement on the CED. The original submission aggregated central values from the 97 papers without propagating their reported errors or adopting conservative defaults. In the revised version we will assign uncertainties to each production rate (using published errors where available and 30-50% fractional uncertainties otherwise), propagate them through the summation to obtain a total-mass-loss uncertainty, and report Mass-Loss Age as 0.16 +0.05/-0.04 comet years with corresponding error bars on the diagram. This will make the horizontal coordinate properly constrained. revision: yes

Referee: The photometric anomaly from -120 to -45 days is labeled an eclipse (and used to infer binarity) solely on the basis of a slope change in the SLC, without light-curve modeling, period search, or evaluation of alternative explanations such as outbursts or data artifacts. This interpretation is central to the broader claim of complexity beyond current understanding.

Authors: The anomaly is identified directly from the SLC constructed with the established SLC-Methodology; the extended flat segment followed by an abrupt slope change is morphologically distinct from the short, peaked profiles of documented outbursts. We did consider data artifacts but found the feature consistent across multiple independent data sets. Nevertheless, we accept that the interpretation would be strengthened by additional analysis. In the revision we will insert a dedicated paragraph explicitly weighing alternative explanations (outbursts, rotational modulation, and possible observational biases), state that the binarity suggestion remains tentative, and clarify that the primary CED placement and Oort-cloud conclusion are independent of this feature. Full light-curve modeling and period searches are noted as desirable future work. revision: partial