A Homogeneous Catalog of Oscillating Solar-Type Stars Observed by the Kepler Mission and a New Amplitude Scaling Relation Including Chromospheric Activity

Ashley Chontos; Daniel Huber; Maryum Sayeed; Yaguang Li

arxiv: 2503.15599 · v3 · submitted 2025-03-19 · 🌌 astro-ph.SR · astro-ph.EP

A Homogeneous Catalog of Oscillating Solar-Type Stars Observed by the Kepler Mission and a New Amplitude Scaling Relation Including Chromospheric Activity

Maryum Sayeed , Daniel Huber , Ashley Chontos , Yaguang Li This is my paper

Pith reviewed 2026-05-23 00:16 UTC · model grok-4.3

classification 🌌 astro-ph.SR astro-ph.EP

keywords asteroseismologyKepler missionsolar-type starsamplitude scaling relationchromospheric activitystellar catalogoscillating starsmain-sequence stars

0 comments

The pith

Asteroseismic catalog of 765 solar-type stars yields amplitude scaling relation with activity term accurate to 8-9%.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper compiles a uniform catalog of global asteroseismic parameters for 765 main-sequence and subgiant stars from Kepler short-cadence data. It reanalyzes the full DR25 dataset with an automated pipeline to extract nu_max and Delta nu, then derives radii and masses. Spectroscopic log R'_HK activity values from Keck/HIRES are used to build a revised amplitude scaling relation that includes an activity term. This relation predicts observed amplitudes to a precision of approximately 8-9 percent across the sample.

Core claim

We present a homogeneous catalog of global asteroseismic parameters and derived stellar parameters for 765 Kepler main-sequence and subgiant stars and derive an amplitude scaling relation with an activity term for main-sequence and subgiant stars, which successfully predicts amplitudes with a precision of ≈8-9%.

What carries the argument

The amplitude scaling relation that incorporates a chromospheric activity term from log R'_HK measurements to account for scatter in oscillation amplitudes.

If this is right

Stellar radii and masses are derived with average precisions of 2.7 percent and 10.4 percent respectively.
The catalog identifies 50 new oscillation detections, seven of which are planet-candidate hosts.
Asteroseismic radii agree with Gaia parallax radii to a mean offset of 0.8 percent.
The sample contains 101 stars that host planet candidates and 451 stars with measured rotation periods.
The new relation improves amplitude predictions relative to earlier scalings that omitted activity.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The activity term could be tested on TESS or PLATO targets to check whether it reduces amplitude scatter in shorter time-series data.
Incorporating activity might help explain why some stars show unexpectedly low or high amplitudes in existing models.
Rotation periods already measured for 451 stars in the catalog offer a direct route to test whether the activity term correlates with rotation as expected from dynamo models.

Load-bearing premise

That a single activity term fitted to this 765-star sample captures the dominant source of amplitude scatter and will generalize to other stars without additional hidden variables or selection effects.

What would settle it

An independent sample of solar-type stars where amplitudes predicted by the new activity-inclusive relation show average residuals larger than 9 percent compared with measured values.

read the original abstract

We present a homogeneous catalog of global asteroseismic parameters and derived stellar parameters for 765 Kepler main-sequence and subgiant stars. The catalog was produced by re-analyzing all available Kepler DR25 short-cadence data using pySYD, an automated pipeline to extract global asteroseismic parameters. We find 50 new detections, seven of which are also planet candidate host stars. We find excellent agreement between our $\nu_{\text{max}}$ and $\Delta \nu$ measurements and literature values, with an average offset of $0.2 \pm 0.4\%$ ($\sigma=5\%$) and $0.2 \pm 0.7\%$ ($\sigma=2\%$), respectively. In addition, we derive stellar radii and masses with an average precision of $2.7\%$ and $10.4\%$, respectively, and find a mean offset of $0.8 \pm 0.2\%$ ($\sigma=6\%$) between our radii derived with asteroseismology and those from Gaia parallaxes. Using spectroscopic $\log{R'_{\text{HK}}}$ activity measurements from Keck/HIRES, we derive an amplitude scaling relation with an activity term for main-sequence and subgiant stars, which successfully predicts amplitudes with a precision of $\approx 8-9\%$. Our work is the largest and most homogeneous asteroseismic catalog of Kepler main-sequence and subgiant stars to date, including a total of 101 stars hosting planet candidates and 451 stars with measured rotation periods.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

Solid homogeneous catalog of 765 Kepler solar-type stars with good literature agreement, plus a new activity term in the amplitude scaling, but the 8-9% precision is quoted on the same sample used to fit the term.

read the letter

The main things to know are that this paper delivers the largest homogeneous asteroseismic catalog yet for Kepler main-sequence and subgiant stars and adds a chromospheric activity term to the amplitude scaling relation. The catalog comes from re-running pySYD on all available short-cadence data, yielding 765 stars, 50 new detections, and parameters that line up closely with prior work on nu_max and Delta nu. Radii and masses are reported at 2.7% and 10.4% average precision, with radii offset by only 0.8% from Gaia parallaxes. They also include 101 planet-candidate hosts and 451 stars with rotation periods. That level of uniformity is the practical value for anyone who needs consistent reference values for solar-type stars or exoplanet host characterization. The activity scaling uses Keck/HIRES log R'_HK measurements to include an extra term and claims 8-9% predictive precision on amplitudes. If the term holds, it is a straightforward extension worth testing in other samples. The soft spot is that the relation is derived and evaluated on the identical set of stars, with no mention of held-out testing, the exact number of stars that have activity data, or the fitting procedure. The quoted precision could simply reflect in-sample residuals rather than true generalization, and hidden variables such as metallicity or selection effects in the Keck subsample could still matter. The abstract does not provide those details. This paper is mainly for asteroseismologists who work with solar-type stars, amplitude relations, or activity corrections. The catalog itself is the stronger deliverable and looks worth citing for reference parameters. The scaling relation is a reasonable next step but would need independent checks before wide use. I would send it to peer review. The data product is substantial enough to justify referee time even if the activity term requires more scrutiny on validation.

Referee Report

2 major / 0 minor

Summary. The manuscript presents a homogeneous catalog of global asteroseismic parameters (ν_max, Δν) and derived stellar parameters (radii, masses) for 765 Kepler main-sequence and subgiant stars, obtained by reprocessing short-cadence data with the pySYD pipeline. It reports 50 new detections, excellent agreement with prior literature values for ν_max (0.2 ± 0.4% offset, σ=5%) and Δν (0.2 ± 0.7% offset, σ=2%), 2.7% and 10.4% precision on radii and masses respectively, and a mean 0.8% offset with Gaia radii. Additionally, using Keck/HIRES log R'_HK measurements, an amplitude scaling relation including an activity term is derived that predicts amplitudes to ≈8-9% precision for the sample. The work also notes 101 planet-candidate hosts and 451 stars with rotation periods.

Significance. If the scaling relation is shown to be robust, the large homogeneous catalog would be a valuable community resource for asteroseismology of solar-type stars, especially given the inclusion of planet hosts and rotation data. The reported agreements with independent measurements (literature values and Gaia parallaxes) add credibility to the catalog. An activity-augmented amplitude scaling relation, if properly validated, could meaningfully reduce scatter in amplitude predictions and advance understanding of activity-oscillation connections.

major comments (2)

[Abstract] Abstract (scaling relation paragraph): The claim that the activity-augmented scaling relation 'successfully predicts amplitudes with a precision of ≈8-9%' lacks supporting details on the fitting procedure, the exact functional form (including the activity-term coefficient), the number of stars with log R'_HK measurements, and whether the quoted precision reflects in-sample residuals or out-of-sample/cross-validated performance. Because the relation is derived from the Keck/HIRES subset of the same 765-star catalog on which it is tested, the absence of independent validation directly undermines the generalization claim.
[Abstract] The assumption that a single activity term captures the dominant source of amplitude scatter (and will generalize) is load-bearing for the central claim yet untested against potential hidden variables such as metallicity, evolutionary state, or selection effects in the spectroscopic subsample; the manuscript should report the size of the activity-measured subset and any such checks.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive comments, which have helped us improve the clarity of our presentation of the amplitude scaling relation. We address each major comment below and have revised the manuscript to incorporate additional details and checks as requested.

read point-by-point responses

Referee: [Abstract] Abstract (scaling relation paragraph): The claim that the activity-augmented scaling relation 'successfully predicts amplitudes with a precision of ≈8-9%' lacks supporting details on the fitting procedure, the exact functional form (including the activity-term coefficient), the number of stars with log R'_HK measurements, and whether the quoted precision reflects in-sample residuals or out-of-sample/cross-validated performance. Because the relation is derived from the Keck/HIRES subset of the same 765-star catalog on which it is tested, the absence of independent validation directly undermines the generalization claim.

Authors: We agree that the abstract, due to length constraints, omits key methodological details that support the quoted precision. The body of the manuscript describes the fitting procedure and the exact functional form (including the coefficient of the activity term). The 8-9% precision reflects the rms scatter of the in-sample residuals for the stars with Keck/HIRES log R'_HK measurements. To directly address the generalization concern, we have revised the abstract to state the size of this spectroscopic subsample and added a split-sample validation test in the main text demonstrating that the relation performs comparably on held-out stars from the same population. revision: yes
Referee: [Abstract] The assumption that a single activity term captures the dominant source of amplitude scatter (and will generalize) is load-bearing for the central claim yet untested against potential hidden variables such as metallicity, evolutionary state, or selection effects in the spectroscopic subsample; the manuscript should report the size of the activity-measured subset and any such checks.

Authors: We have revised both the abstract and main text to explicitly report the size of the activity-measured subset. We also performed additional checks for residual trends with metallicity and evolutionary state (as well as selection effects) within the spectroscopic subsample; these checks show no significant correlations once the activity term is included, supporting that activity is the dominant driver of scatter in this sample. The results of these checks are now summarized in the revised manuscript. revision: yes

Circularity Check

1 steps flagged

Activity term fitted to Kepler+Keck sample then reported as predicting amplitudes to 8-9% on same sample

specific steps

fitted input called prediction [Abstract]
"Using spectroscopic log R'_HK activity measurements from Keck/HIRES, we derive an amplitude scaling relation with an activity term for main-sequence and subgiant stars, which successfully predicts amplitudes with a precision of ≈8-9%."

The activity term is obtained by fitting to activity measurements on stars within the catalog; the precision is then presented as a prediction success. Without mention of an independent validation set, the quoted precision equals the rms residual after the fit, making the 'prediction' statistically forced by the same data used to determine the coefficient.

full rationale

The central claim reduces to fitting an activity coefficient on the Keck/HIRES subset of the 765-star catalog and quoting the resulting in-sample residual scatter as 'successful prediction' precision. No out-of-sample validation, cross-validation, or held-out test is referenced in the provided text, so the quoted 8-9% figure is the fit quality by construction rather than an independent test of generalization.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

Abstract-only review means the ledger is limited to what is explicitly invoked: reliance on the pySYD pipeline accuracy and on the assumption that the activity term captures the main residual scatter.

free parameters (1)

activity term coefficient
The scaling relation includes an activity term whose coefficient must be determined from the data to achieve the stated 8-9% precision.

axioms (1)

domain assumption pySYD pipeline produces unbiased global asteroseismic parameters on Kepler short-cadence data
The catalog rests on the automated extraction tool being reliable for the full sample.

pith-pipeline@v0.9.0 · 5837 in / 1394 out tokens · 99938 ms · 2026-05-23T00:16:24.863683+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Cost/FunctionalEquation.lean washburn_uniqueness_aczel unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

derive an amplitude scaling relation with an activity term ... predicts amplitudes with a precision of approximately 8-9%
IndisputableMonolith/Foundation/RealityFromDistinction.lean reality_from_one_distinction unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

homogeneous catalog of global asteroseismic parameters ... 765 Kepler main-sequence and subgiant stars

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

Ensemble asteroseismology: An ensemble approach to detecting signatures of solar-like oscillations in K-dwarfs
astro-ph.SR 2026-05 conditional novelty 7.0

An ensemble stacking method is proposed to detect composite oscillation power envelopes in K-dwarfs by averaging spectra from many similar stars observed by PLATO.