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REVIEW 3 major objections 7 minor 67 references

Seismic Signatures of Stellar Magnetic Activity -- What Can We Expect from TESS?

T0 review · 3 major / 7 minor · reviewed 2026-08-14 · deepseek-v4-flash

Pith's one-line read An extended TESS mission should detect activity-driven p-mode frequency shifts in a few thousand evolved stars, turning a rare seismic measurement into a survey-scale result.

desk verdict A candid, conditional forecast: the TESS yield numbers rest on openly admitted ad hoc scaling factors, but the paper is honest, useful, and its Section 7 bias warning is a genuine contribution. read the letter →

arxiv 1908.01191 v1 pith:RRB4PTY3 submitted 2019-08-03 astro-ph.SR

classification astro-ph.SR
keywords stellaractivityasteroseismologycyclesTESSp-modefrequencyshiftssolar-likeoscillationsscalingrelationsredgiants
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

Extending NASA's TESS mission by four years should turn asteroseismic detection of stellar magnetic activity from a rare occurrence into a survey-scale result. The paper derives a scaling relation that predicts the size of activity-driven p-mode frequency shifts over a full stellar activity cycle, then injects those shifts into a synthetic catalogue of TESS light curves and measures how many would be detected with cross-correlation and peak-bagging methods. It predicts significant shifts in a couple hundred main-sequence and early subgiant stars and a few thousand late subgiant and low-luminosity red giants. This matters because only a few dozen stars currently have measured activity-related frequency shifts; a few thousand would allow the dependence of stellar dynamos on mass, age, and rotation to be mapped.

What carries the argument

The load-bearing object is a scaling relation for the amplitude of activity-related acoustic-mode frequency shifts: δν ∝ [R/(M νmax)] ΔR′HK,mod, where R′HK,mod divides an observed chromospheric activity index by R², by max(√(Ro−1),1) for stars with Rossby numbers above about 2, and by √tage. A companion relation, Pcyc = 0.5 Prot max(√(Ro−1),1), converts full-cycle shifts into the frequency shift expected between two TESS epochs separated by two or four years. The detection pipeline shifts a synthetic power spectrum by that predicted amount and measures the shift back with a cross-correlation technique, using a synthetic catalogue of 12,731 TESS short-cadence targets as the test population.

What would settle it

Take the existing four-year Kepler light curves of low-luminosity red giants with νmax between about 30 and 300 μHz, measure their p-mode frequency shifts between epochs with the cross-correlation method, and compare the distribution with the shifts predicted by the paper's scaling relation: if typical measured shifts are below about 0.1 μHz rather than the predicted several tenths to μHz, the forecast of thousands of TESS detections is not realized.

Watch

Extended reading notes

Core claim

The paper's central claim is that activity-related p-mode frequency shifts are not only present but abundant in an extended TESS mission. Using a new scaling relation, δν ∝ R/(M νmax) ΔR′HK,mod, where the modified calcium activity index is divided by stellar surface area, a Rossby-number transition factor, and age, the predicted full-cycle shifts are roughly 6 μHz for a low-luminosity red giant, whereas an earlier scaling relation would give over 50 μHz. Simulating detection with a cross-correlation technique on the synthetic TESS sample, the paper finds, for a four-year extension, significant shifts in 171 main-sequence/early subgiant stars and 2275 evolved subgiant and low-luminosity red giants with the cross-correlation method, and 717 and 3087 with the peak-bagging uncertainty assumption. For a two-year extension the totals are 2349 and 3305. The shifts should be measurable even in single-sector observations, and the paper argues that shifts of several μHz at νmax would bias asteroseismic mass and radius estimates unless global seismic parameters are calibrated for activity level.

Load-bearing premise

The predicted counts rest on the assumption that the paper's modified activity indicator—an observed chromospheric-emission measure divided by extra factors for surface area, a rotation-activity transition, and stellar age—describes how real full-cycle frequency shifts scale for evolved stars; if that scaling is wrong, the yields change by factors of several.

Editorial extensions

If this is right

  • A four-year TESS extension should yield significant activity-related frequency shifts in 171 main-sequence and early subgiant stars (717 with the peak-bagging uncertainty assumption) and 2275 late subgiants and low-luminosity red giants (3087 with peak-bagging).
  • Most detected stars are cooler than about 6500 K; F-type stars make up only a small fraction of detections because their broad mode peaks hide small shifts.
  • Even stars observed in a single TESS sector can show measurable shifts, so the search is not limited to continuous long-baseline targets.
  • Activity shifts of several μHz at νmax would cause asteroseismic scaling relations to overestimate stellar mass and radius unless global parameters are calibrated for activity level.
  • The predicted yields and shift amplitudes differ enough among the three competing scaling relations that an extended TESS sample could discriminate between them observationally.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Beyond the paper: because the same scaling relation predicts that activity shifts should already be present in four-year Kepler light curves of low-luminosity red giants, re-analysing existing Kepler data would test the relation before TESS is extended; the paper notes such a study is in preparation but does not use it as evidence.
  • Beyond the paper: if the peak-bagging uncertainty assumption (half the cross-correlation uncertainty) is too optimistic, the true detectable yield will sit between the cross-correlation and peak-bagging columns, roughly 2400 to 3800 stars for a four-year extension.
  • Beyond the paper: the same relation implies that ensemble asteroseismic masses and radii for red giants, used in Galactic archaeology, may carry a small activity-dependent bias even when individual shifts are not the target; calibrating νmax and Δν for activity could reduce that bias.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 7 minor

Summary. This paper predicts how many activity-related p-mode frequency shifts can be detected in an extended TESS mission. The authors derive a new scaling relation for full-cycle frequency shifts, δν ∝ (R/M ν_max) ΔR'_HK,mod (Eq. 15), combining a mode-sensitivity factor derived in Section 3 (Eqs. 4-11) with a modified Ca II H&K activity index that includes surface-area dilution, a Rossby-number cutoff, and an age-degradation factor (Eq. 14). Using the synthetic TESS light-curve catalogue of Ball et al. (2018), they inject into each power spectrum the frequency shift expected over a two- or four-year gap under an assumed cycle-period formula (Eqs. 17-18) and measure shifts with a cross-correlation technique, approximating peak-bagging uncertainties as half the CC uncertainties. Their central result is the yield forecast in Table 1: for a four-year extension, a couple hundred main-sequence and early subgiant stars (171 CC, 717 PB) and a few thousand late subgiant and low-luminosity red giants (2275 CC, 3087 PB) would show significant frequency shifts. The paper additionally argues (Section 7) that unaccounted activity shifts would bias asteroseismic mass and radius estimates from the standard scaling relations.

Significance. If the forecast holds, it is a transformative result for stellar activity-cycle science: the sample of stars with detected activity-related seismic frequency shifts would grow from a few dozen to thousands, enabling systematic study of dynamo behaviour across mass, age, and rotation. The paper has real strengths: the derivation of the mode-sensitivity factor is transparent and is shown to agree with Metcalfe et al. (2007) to within a factor of √T_eff (0.91-1.14); the absolute scale is anchored by the solar 0.4 μHz calibration; the simulation is built on a public synthetic catalogue with stated data availability; a false-positive test under zero input shift is performed; and Section 7 yields a concrete, falsifiable consequence for asteroseismic scaling relations. The forecast itself is falsifiable with extended TESS data. The principal weakness is that the region-II yield, which dominates the numbers, is extrapolated through a scaling relation whose evolved-star behaviour is adjusted by hand in Section 5 and is unanchored by any confirmed detection in subgiants or red giants, as the paper itself acknowledges.

major comments (3)
  1. [Section 5, Eq. (14)] The three activity-evolution factors in Eq. (14) — the R^-2 surface-area dilution, the max(sqrt(Ro-1),1) Rossby cutoff, and the t_Age^-0.5 decay — are introduced after the fact because the unmodified Metcalfe et al. relation gives full-cycle shifts above 50 μHz on the lower red giant branch; Section 5 states that 'this is why we looked for reasonable adjustments.' Since Eq. (15) feeds directly into the injected shifts via Eq. (18) and hence into the Table 1 detection counts, the headline yield (171 CC / 717 PB detections in region I; 2275 CC / 3087 PB in region II for a four-year extension) is fully conditional on the magnitudes and functional forms of three hand-chosen factors. The manuscript itself concedes (Section 5) that activity may decline faster than t^-0.5 or stop entirely at some evolutionary stage, and that the same uncertainty applies to the Rossby factor, and it states (Section 8) that the relation may not be valid even with the adjustments. No evolved-star data anchor these choices, since the comparison in Section 6.1 is restricted to main-sequence stars and the paper notes there is currently no confirmed frequency-shift detection in subgiants or red giants. Please add a sensitivity analysis of Table 1 with respect to each factor (including omitting them individually and varying the age exponent), and quote the yield as a range or explicitly label it as conditional on the adopted scaling.
  2. [Section 4, Eqs. (17)-(18)] The fraction of the full-cycle shift that appears in the two- or four-year gap is set entirely by the cycle-period estimate through Eq. (18), and Eq. (17) is described in Section 5 as 'obviously very crude.' Because most of the predicted detections are in region II, where cycles are long and the min(2n/P_cyc,1) factor suppresses the injected shift, a factor-of-two error in P_cyc directly changes the injected δν and therefore changes which stars clear the significance threshold in Tables 1-4. The yield columns should be re-computed for a range of plausible P_cyc scalings (for example, P_cyc multiplied by 0.5 and 2.0, or using the observed short-cycle and long-cycle branches separately) so that the dependence of the forecast on this admittedly crude input is quantified in the paper rather than left implicit.
  3. [Sections 4 and 6, detection criterion] The definition of a 'significant frequency shift' as one that is 'at least 1σ > 0' and within 3σ of the input shift is weak on the first condition, and the false-positive test described in Section 6 is reported only for the PB method ('We found no false positives detections with the PB method'), even though the primary numbers in Table 1 are CC detections. Under a pure-noise realisation with zero input shift, the condition 'at least 1σ > 0' would by itself admit roughly 16% of a Gaussian noise distribution, so the reported absence of false positives is non-trivial and needs an explanation. Please report the CC false-positive rate explicitly, describe how the detection thresholds interact with the Lorentzian fit of the cross-correlation function, and justify the asymmetric 1σ threshold.
minor comments (7)
  1. [Section 3, Eqs. (14)-(15)] Equation (15) uses ΔR'_HK,mod, but Eq. (14) defines only R'_HK,mod; please state explicitly that ΔR'_HK,mod is obtained by applying the Saar-Brandenburg relation in Eq. (1) to R'_HK,mod, as the text currently leaves this inference implicit.
  2. [Section 2, abstract, Section 6] Region I is defined in Section 2 as the main sequence (pre-TAMS, core hydrogen abundance above 10^-5), but the abstract and Section 6 describe region I as 'main-sequence and early subgiant stars'; please reconcile this terminology so the reader can map the abstract's claim onto the Table 1 rows.
  3. [Figure 9] The caption of Figure 9 says 'As Figure 1 but for the full-cycle frequency shifts,' which appears to be a typo for 'As Figure 2.'
  4. [Section 6, typographical errors] The sentence 'We found no false positives detections with the PB method' contains the word 'detections' where 'detections' is repeated awkwardly, and 'omitting' is misspelled as 'ommiting' in the same paragraph; both should be corrected in a final pass.
  5. [Section 5, PB vs CC uncertainty] The assumption that peak-bagging uncertainties are smaller than cross-correlation uncertainties by a factor of two is stated without justification; a reference to the comparison studies cited in Section 4 or a brief sensitivity statement would help the reader interpret the PB columns of Tables 1-4.
  6. [Data Availability Statement] The Data Availability Statement gives only the word 'Link' as the repository address; please provide the actual URL or a DOI.
  7. [Section 3, Figure 2] The 6500 K spike in Figure 2, attributed to the rotation-period modelling transition in Ball et al., is mentioned in the text; please quantify how many of the region-I F-star detections in Table 1 lie in the affected temperature range so that the influence of this modelling artifact on the quoted F-star fractions is explicit.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the TESS yield forecast is a forward simulation conditional on an explicitly labeled scaling relation, not a fit disguised as a prediction.

full rationale

The central yield forecast is a forward model, not a circular derivation. The scaling relation in Eq. (15) is calibrated externally to the solar frequency shift of 0.4 microhertz and built from published empirical relations (Saar & Brandenburg, Noyes et al., Metcalfe et al.) that are not derived from the predicted sample. The three modifications in Eq. (14) are introduced after the paper notes that the unmodified Metcalfe relation gives implausibly large shifts for low-luminosity red giants ('This is why we looked for reasonable adjustments.'), but these factors have no free parameters fitted to the target data and are explicitly described as an 'attempt to circumvent our ignorance' rather than as measured constraints. Likewise, the cycle-period estimate in Eq. (17) is labeled 'obviously very crude' and is an input assumption, not an output of the derivation. The detection simulation injects shifts computed from Eq. (15) and measures them with cross-correlation and peak-bagging; the resulting counts are conditional on the scaling relation, which the paper repeatedly states ('according to our scaling relation'). The comparison with Santos et al. (2018) is an external empirical check, even though one author overlaps, and the self-citations to Kiefer et al. (2017) are used as observational context rather than as the proof of the new scaling relation. The admitted uncertainties in the activity-evolution factors and cycle periods are robustness concerns, not circularity.

Assumptions & free parameters 5 free parameters · 6 assumptions · 0 invented entities

The central forecast is built from one externally calibrated physical scaling, one empirical activity proxy, and several hand-chosen evolutionary adjustments. The free parameters are not fitted to the Kepler shift data, but neither are they derived from an independent theory; they are selected to keep red-giant shifts plausible. The ledger shows that the paper's novelty and risk both live in the same place: the modified R'_HK relation and the cycle-period formula.

free parameters (5)
  • Surface-area dilution factor R^-2 = exponent -2
    Introduced in Equation (14) as a hand-chosen way to reduce activity-related shifts for evolved, larger stars; no derivation or calibration.
  • Rossby number activity cutoff = Ro_crit = 2, sqrt(Ro-1) scaling
    Added to Equations (14) and (17) to model the Metcalfe and van Saders (2017) activity transition; functional form chosen ad hoc.
  • Age-degradation power = t_Age^-0.5
    Skumanich (1972) aging law extrapolated to post-main-sequence stars in Equation (14); the authors state the extrapolation is uncertain.
  • Cycle-period coefficient = 0.5 P_rot in Equation 17
    Chosen as a rather crude estimation as a compromise between short and long cycle branches; directly controls the observed shift fraction.
  • PB to CC uncertainty ratio = 1/2
    Assumed peak-bagging uncertainties are half of cross-correlation uncertainties; this assumption boosts the PB yield numbers.
assumptions (6)
  • domain assumption Equation (4) variational expression for frequency shifts
    Adopted from Metcalfe et al. (2007); assumes a sensitivity kernel and a localized source function.
  • domain assumption Saar and Brandenburg amplitude relation Delta R'_HK proportional to R'_HK^0.77
    Empirical relation from main-sequence stars used to convert activity index to cycle amplitude.
  • domain assumption Noyes et al. rotation-activity relation (Equation 12)
    Calibrated on main-sequence stars but applied to subgiants and red giants in the synthetic sample.
  • ad hoc to paper Approximations in Equations (8) to (11): derivative replaced by xi_r/r, inertia as R^3 rho |xi|^2, source at photosphere
    Crude approximations; the authors show the final sensitivity differs from Metcalfe et al. by only sqrt(Teff).
  • domain assumption Synthetic TESS sample of Ball et al. (2018) is representative of real TESS ATL targets
    All yield numbers inherit the sample's modelling of rotation, ages, and mode parameters.
  • domain assumption Activity does not suppress oscillation amplitudes in the simulation
    Explicitly not modelled; the authors argue the affected stars are a small subset.

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Cite this review

Pith. "Pith review of Seismic Signatures of Stellar Magnetic Activity -- What Can We Expect from TESS?." pith.science (2026). https://pith.science/paper/RRB4PTY3

@misc{pith2026190801191,
  author       = {Pith},
  title        = {Pith review of: Seismic Signatures of Stellar Magnetic Activity -- What Can We Expect from TESS?},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/RRB4PTY3}},
  note         = {Machine review of arXiv:1908.01191}
}
read the original abstract

Asteroseismic methods offer a means to investigate stellar activity and activity cycles as well as to identify those properties of stars which are crucial for the operation of stellar dynamos. With data from CoRoT and \textit{Kepler}, signatures of magnetic activity have been found in the seismic properties of a few dozen stars. Now, NASA's Transiting Exoplanet Survey Satellite (TESS) mission offers the possibility to expand this, so far, rather exclusive group of stars. This promises to deliver new insight into the parameters that govern stellar magnetic activity as a function of stellar mass, age, and rotation rate. We derive a new scaling relation for the amplitude of the activity-related acoustic (p-mode) frequency shifts that can be expected over a full stellar cycle. Building on a catalogue of synthetic TESS time series, we use the shifts obtained from this relation and simulate the yield of detectable frequency shifts in an extended TESS mission. We find that, according to our scaling relation, we can expect to find significant p-mode frequency shifts for a couple hundred main-sequence and early subgiant stars and for a few thousand late subgiant and low-luminosity red giant stars.

Figures

Figures reproduced from arXiv: 1908.01191 by the authors.

Figure 1
Figure 1. Kiel diagram of the synthetic TESS sample of Ball et al. [41]. The age of the stars is given by the colour of the dots. The Sun is indicated by its usual symbol. Evolutionary tracks for stars with masses from 0.8 to 2.0 M in steps of 0.2 M are overlaid as solid black lines. 3 RECONSIDERING THE SCALING RELATION FOR P-MODE FREQUENCY SHIFTS There are two models for activity related frequency shifts in the literature: C… view at source ↗
Figure 2
Figure 2. Frequency shift amplitudes for full activity cycles for the synthetic TESS sample calculated with Equation (15). The colour of the dots indicates stellar age. The Sun is indicated by its usual symbol [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. As [PITH_FULL_IMAGE:figures/full_fig_p010_3.png] view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: Significant frequency shifts of the synthetic TESS sample for: (a) all stars as a function of effective temperature; (b) all stars as a function of rotation period; (c) stars in region I as a function of effective temperature; (d) stars in region I as a function of rot…
Figure 5
Figure 5. Figure 5: Same as [PITH_FULL_IMAGE:figures/full_fig_p014_5.png]
Figure 6
Figure 6. Figure 6: Left panel: Significant frequency shifts from region I of the synthetic TESS data as function of effective temperature in red. A four year extension of the TESS mission is assumed and the error bars of the CC method are halved to approximate the PB method. Significant …
Figure 7
Figure 7. Figure 7: Kiel diagram of the synthetic TESS sample of Ball et al. [41]. The Sun is indicated by its usual symbol. Evolutionary tracks for stars with masses from 0.8 to 2.0 M in steps of 0.2 M are overlaid as solid black lines. Stars on the main-sequence are blue, stars after th…
Figure 8
Figure 8. Figure 8: As [PITH_FULL_IMAGE:figures/full_fig_p025_8.png]
Figure 9
Figure 9. Figure 9: As [PITH_FULL_IMAGE:figures/full_fig_p025_9.png]

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Works this paper leans on

67 extracted references · 22 canonical work pages

  1. [1]

    Chromospheric variations in main-sequence stars

    Baliunas SL, Donahue RA, Soon WH, Horne JH, Frazer J, Woodard-Eklund L, et al. Chromospheric variations in main-sequence stars. Astrophys. J. 438 (1995) 269–287. doi:10.1086/175072

  2. [2]

    Time Evolution of the Magnetic Activity Cycle Period

    Saar SH, Brandenburg A. Time Evolution of the Magnetic Activity Cycle Period. II. Results for an Expanded Stellar Sample. Astrophys. J. 524 (1999) 295–310. doi:10.1086/307794

  3. [3]

    Looking for activity cycles in late-type Kepler stars using time-frequency analysis

    Vida K, Ol´ah K, Szab´o R. Looking for activity cycles in late-type Kepler stars using time-frequency analysis. Mon. Notices R. Astron. Soc. 441 (2014) 2744–2753. doi:10.1093/mnras/stu760

  4. [4]

    Solar activity cycle frequency shifts of low-degree p-modes

    Jim´enez-Reyes SJ, R ´egulo C, Pall ´e PL, Roca Cort ´es T. Solar activity cycle frequency shifts of low-degree p-modes. Astron. Astrophys. 329 (1998) 1119–1124

  5. [5]

    A Helioseismic Perspective on the Depth of the Minimum Between Solar Cycles 23 and 24

    Broomhall AM. A Helioseismic Perspective on the Depth of the Minimum Between Solar Cycles 23 and 24. Solar Phys. 292 (2017) 67. doi:10.1007/s11207-017-1068-5

  6. [6]

    A Comparison Between Global Proxies of the Sun’s Magnetic Activity Cycle: Inferences from Helioseismology

    Broomhall AM, Nakariakov VM. A Comparison Between Global Proxies of the Sun’s Magnetic Activity Cycle: Inferences from Helioseismology. Solar Phys. 290 (2015) 3095–3111. doi:10.1007/ s11207-015-0728-6

  7. [7]

    Scientific Objectives for a Minisat: CoRoT

    Baglin A, Auvergne M, Barge P, Deleuil M, Catala C, Michel E, et al. Scientific Objectives for a Minisat: CoRoT. Fridlund M, Baglin A, Lochard J, Conroy L, editors,The CoRoT Mission Pre-Launch Status - Stellar Seismology and Planet Finding (2006), ESA Special Publication, vol. 1306, 33

  8. [9]

    CoRoT Reveals a Magnetic Activity Cycle in a Sun-Like Star

    Garc´ıa RA, Mathur S, Salabert D, Ballot J, R´egulo C, Metcalfe TS, et al. CoRoT Reveals a Magnetic Activity Cycle in a Sun-Like Star. Science 329 (2010) 1032. doi:10.1126/science.1191064

Show all 67 references
  1. [10]

    The spectrum of solar p-modes and the solar activity cycle

    Pall´e P, R´egulo C, Roca Cort´es T. The spectrum of solar p-modes and the solar activity cycle. Osaki Y , Shibahashi H, editors,Progress of Seismology of the Sun and Stars (Springer Berlin Heidelberg), Lecture Notes in Physics, vol. 367 (1990), 129–134. doi:10.1007/3-540-53091-6 73

  2. [11]

    Width and Energy of Solar p-Modes Observed by Global Oscillation Network Group

    Komm RW, Howe R, Hill F. Width and Energy of Solar p-Modes Observed by Global Oscillation Network Group. Astrophys. J. 543 (2000) 472–485. doi:10.1086/317101. This is a provisional file, not the final typeset article 18 Kiefer et al. Seismic Signatures of Stellar Magnetic Activity

  3. [12]

    About the p-mode frequency shifts in HD 49933

    Salabert D, R ´egulo C, Ballot J, Garc ´ıa RA, Mathur S. About the p-mode frequency shifts in HD 49933. Astron. Astrophys. 530 (2011) A127. doi:10.1051/0004-6361/201116633

  4. [13]

    Solar-cycle effects on solar oscillation frequencies

    Libbrecht KG, Woodard MF. Solar-cycle effects on solar oscillation frequencies. Nature 345 (1990) 779–782. doi:10.1038/345779a0

  5. [14]

    Solar p modes in 10 years of the IRIS network

    Salabert D, Fossat E, Gelly B, Kholikov S, Grec G, Lazrek M, et al. Solar p modes in 10 years of the IRIS network. Astron. Astrophys. 413 (2004) 1135–1142. doi:10.1051/0004-6361:20031541

  6. [15]

    Kepler planet-detection mission: Introduction and first results

    Borucki WJ, Koch D, Basri G, Batalha N, Brown T, Caldwell D, et al. Kepler planet-detection mission: Introduction and first results. Science 327 (2010) 977–980. doi:10.1126/science.1185402

  7. [16]

    Kepler Mission Design, Realized Photometric Performance, and Early Science

    Koch DG, Borucki WJ, Basri G, Batalha NM, Brown TM, Caldwell D, et al. Kepler Mission Design, Realized Photometric Performance, and Early Science. Astrophys. J. Lett. 713 (2010) L79-L86. doi:10.1088/2041-8205/713/2/L79

  8. [17]

    Magnetic variability in the young solar analog KIC 10644253

    Salabert D, R ´egulo C, Garc´ıa RA, Beck PG, Ballot J, Creevey OL, et al. Magnetic variability in the young solar analog KIC 10644253. Observations from the Kepler satellite and the HERMES spectrograph. Astron. Astrophys. 589 (2016) A118. doi:10.1051/0004-6361/201527978

  9. [19]

    Stellar magnetic activity and variability of oscillation parameters: An investigation of 24 solar-like stars observed by Kepler

    Kiefer R, Schad A, Davies G, Roth M. Stellar magnetic activity and variability of oscillation parameters: An investigation of 24 solar-like stars observed by Kepler. Astron. Astrophys. 598 (2017) A77. doi:10.1051/0004-6361/201628469

  10. [20]

    Frequency dependence of p-mode frequency shifts induced by magnetic activity in Kepler solar-like stars

    Salabert D, R´egulo C, P´erez Hern´andez F, Garc´ıa RA. Frequency dependence of p-mode frequency shifts induced by magnetic activity in Kepler solar-like stars. Astron. Astrophys. 611 (2018) A84. doi:10.1051/0004-6361/201731714

  11. [21]

    Signatures of Magnetic Activity in the Seismic Data of Solar-type Stars Observed by Kepler

    Santos ˆARG, Campante TL, Chaplin WJ, Cunha MS, Lund MN, Kiefer R, et al. Signatures of Magnetic Activity in the Seismic Data of Solar-type Stars Observed by Kepler. Astrophys. J. Suppl. Series 237 (2018) 17. doi:10.3847/1538-4365/aac9b6

  12. [22]

    Evidence for the Impact of Stellar Activity on the Detectability of Solar-like Oscillations Observed by Kepler

    Chaplin WJ, Bedding TR, Bonanno A, Broomhall AM, Garc ´ıa RA, Hekker S, et al. Evidence for the Impact of Stellar Activity on the Detectability of Solar-like Oscillations Observed by Kepler. Astrophys. J. Lett. 732 (2011) L5. doi:10.1088/2041-8205/732/1/L5

  13. [23]

    Chromospheric Activity in G and K Main-Sequence Stars, and What It Tells Us about Stellar Dynamos

    B¨ohm-Vitense E. Chromospheric Activity in G and K Main-Sequence Stars, and What It Tells Us about Stellar Dynamos. Astrophys. J. 657 (2007) 486–493. doi:10.1086/510482

  14. [24]

    Improved Age Estimation for Solar-Type Dwarfs Using Activity- Rotation Diagnostics

    Mamajek EE, Hillenbrand LA. Improved Age Estimation for Solar-Type Dwarfs Using Activity- Rotation Diagnostics. Astrophys. J. 687 (2008) 1264–1293. doi:10.1086/591785

  15. [25]

    Magnetic cycles and rotation periods of late-type stars from photometric time series

    Su´arez Mascare˜no A, Rebolo R, Gonz ´alez Hern´andez JI. Magnetic cycles and rotation periods of late-type stars from photometric time series. Astron. Astrophys. 595 (2016) A12. doi:10.1051/ 0004-6361/201628586

  16. [26]

    Magnetic Evolution and the Disappearance of Sun-Like Activity Cycles

    Metcalfe TS, van Saders J. Magnetic Evolution and the Disappearance of Sun-Like Activity Cycles. Solar Phys. 292 (2017) 126. doi:10.1007/s11207-017-1157-5

  17. [27]

    Reconciling solar and stellar magnetic cycles with nonlinear dynamo simulations

    Strugarek A, Beaudoin P, Charbonneau P, Brun AS, do Nascimento JD. Reconciling solar and stellar magnetic cycles with nonlinear dynamo simulations. Science 357 (2017) 185–187. doi:10.1126/ science.aal3999

  18. [28]

    Dynamo cycles in global convection simulations of solar-like stars

    Warnecke J. Dynamo cycles in global convection simulations of solar-like stars. Astron. Astrophys. 616 (2018) A72. doi:10.1051/0004-6361/201732413

  19. [29]

    On the Sensitivity of Magnetic Cycles in Global Simulations of Solar-like Stars

    Strugarek A, Beaudoin P, Charbonneau P, Brun AS. On the Sensitivity of Magnetic Cycles in Global Simulations of Solar-like Stars. Astrophys. J. 863 (2018) 35. doi:10.3847/1538-4357/aacf9e. Frontiers 19 Kiefer et al. Seismic Signatures of Stellar Magnetic Activity

  20. [30]

    Inferences on Stellar Activity and Stellar Cycles from Asteroseismology

    Chaplin WJ, Basu S. Inferences on Stellar Activity and Stellar Cycles from Asteroseismology. Space Sci. Rev. 186 (2014) 437–456. doi:10.1007/s11214-014-0090-2

  21. [31]

    The variability of magnetic activity in solar-type stars

    Fabbian D, Simoniello R, Collet R, Criscuoli S, Korhonen H, Krivova NA, et al. The variability of magnetic activity in solar-type stars. Astronomische Nachrichten 338 (2017) 753–772. doi:10.1002/ asna.201713403

  22. [32]

    Total Solar Irradiance: What Have We Learned from the Last Three Cycles and the Recent Minimum? Space Sci

    Fr¨ohlich C. Total Solar Irradiance: What Have We Learned from the Last Three Cycles and the Recent Minimum? Space Sci. Rev. 176 (2013) 237–252. doi:10.1007/s11214-011-9780-1

  23. [33]

    The nature of solar brightness variations

    Shapiro AI, Solanki SK, Krivova NA, Cameron RH, Yeo KL, Schmutz WK. The nature of solar brightness variations. Nature Astronomy 1 (2017) 612–616. doi:10.1038/s41550-017-0217-y

  24. [34]

    Variability of Sun-like stars: reproducing observed photometric trends

    Shapiro AI, Solanki SK, Krivova NA, Schmutz WK, Ball WT, Knaack R, et al. Variability of Sun-like stars: reproducing observed photometric trends. Astron. Astrophys. 569 (2014) A38. doi:10.1051/ 0004-6361/201323086

  25. [35]

    Photometric magnetic-activity metrics tested with the Sun: application to Kepler M dwarfs

    Mathur S, Salabert D, Garc´ıa RA, Ceillier T. Photometric magnetic-activity metrics tested with the Sun: application to Kepler M dwarfs. Journal of Space Weather and Space Climate 4 (2014) A15. doi:10.1051/swsc/2014011

  26. [36]

    Photospheric and chromospheric magnetic activity of seismic solar analogs

    Salabert D, Garc ´ıa RA, Beck PG, Egeland R, Pall ´e PL, Mathur S, et al. Photospheric and chromospheric magnetic activity of seismic solar analogs. Observational inputs on the solar-stellar connection from Kepler and Hermes. Astron. Astrophys. 596 (2016) A31. doi:10.1051/0004...

  27. [37]

    Photospheric activity of the Sun with VIRGO and GOLF

    Salabert D, Garc´ıa RA, Jim´enez A, Bertello L, Corsaro E, Pall´e PL. Photospheric activity of the Sun with VIRGO and GOLF. Comparison with standard activity proxies. Astron. Astrophys. 608 (2017) A87. doi:10.1051/0004-6361/201731560

  28. [38]

    Stellar cycles from photometric data: CoRoT stars

    Ferreira Lopes CE, Le˜ao IC, de Freitas DB, Canto Martins BL, Catelan M, De Medeiros JR. Stellar cycles from photometric data: CoRoT stars. Astron. Astrophys. 583 (2015) A134. doi:10.1051/ 0004-6361/201424900

  29. [39]

    Long-term Photometric Variability in Kepler Full-frame Images: Magnetic Cycles of Sun-like Stars

    Montet BT, Tovar G, Foreman-Mackey D. Long-term Photometric Variability in Kepler Full-frame Images: Magnetic Cycles of Sun-like Stars. Astrophys. J. 851 (2017) 116. doi:10.3847/1538-4357/ aa9e00

  30. [40]

    Sounding stellar cycles with Kepler - III

    Karoff C, Metcalfe TS, Montet BT, Jannsen NE, Santos ARG, Nielsen MB, et al. Sounding stellar cycles with Kepler - III. Comparative analysis of chromospheric, photometric, and asteroseismic variability. Mon. Notices R. Astron. Soc. 485 (2019) 5096–5104. doi:10.1093/mnras/stz782

  31. [41]

    A Synthetic Sample of Short-cadence Solar-like Oscillators for TESS

    Ball WH, Chaplin WJ, Schofield M, Miglio A, Bossini D, Davies GR, et al. A Synthetic Sample of Short-cadence Solar-like Oscillators for TESS. Astrophys. J. Suppl. Series 239 (2018) 34. doi:10. 3847/1538-4365/aaedbc

  32. [42]

    Transiting Exoplanet Survey Satellite (TESS)

    Ricker GR, Winn JN, Vanderspek R, Latham DW, Bakos G´A, Bean JL, et al. Transiting Exoplanet Survey Satellite (TESS). Journal of Astronomical Telescopes, Instruments, and Systems 1 (2015) 014003. doi:10.1117/1.JATIS.1.1.014003

  33. [43]

    Star counts in the Galaxy

    Girardi L, Groenewegen MAT, Hatziminaoglou E, da Costa L. Star counts in the Galaxy. Simulating from very deep to very shallow photometric surveys with the TRILEGAL code. Astron. Astrophys. 436 (2005) 895–915. doi:10.1051/0004-6361:20042352

  34. [44]

    The Asteroseismic Target List for Solar-like Oscillators Observed in 2 minute Cadence with the Transiting Exoplanet Survey Satellite

    Schofield M, Chaplin WJ, Huber D, Campante TL, Davies GR, Miglio A, et al. The Asteroseismic Target List for Solar-like Oscillators Observed in 2 minute Cadence with the Transiting Exoplanet Survey Satellite. Astrophys. J. Suppl. Series 241 (2019) 12. doi:10.3847/1538-4365/ab04f5

  35. [45]

    Amplitudes of stellar oscillations: the implications for asteroseismology

    Kjeldsen H, Bedding TR. Amplitudes of stellar oscillations: the implications for asteroseismology. Astron. Astrophys. 293 (1995) 87–106. This is a provisional file, not the final typeset article 20 Kiefer et al. Seismic Signatures of Stellar Magnetic Activity

  36. [46]

    The Asteroseismic Potential of TESS: Exoplanet-host Stars

    Campante TL, Schofield M, Kuszlewicz JS, Bouma L, Chaplin WJ, Huber D, et al. The Asteroseismic Potential of TESS: Exoplanet-host Stars. Astrophys. J. 830 (2016) 138. doi:10.3847/0004-637X/830/ 2/138

  37. [47]

    On prospects for sounding activity cycles of Sun-like stars with acoustic modes

    Chaplin WJ, Elsworth Y , Houdek G, New R. On prospects for sounding activity cycles of Sun-like stars with acoustic modes. Mon. Notices R. Astron. Soc. 377 (2007) 17–29. doi:10.1111/j.1365-2966. 2007.11581.x

  38. [48]

    A new look at dynamo cycle amplitudes

    Saar SH, Brandenburg A. A new look at dynamo cycle amplitudes. Astronomische Nachrichten 323 (2002) 357–360. doi:10.1002/1521-3994(200208)323:3/4⟨357::AID-ASNA357⟩3.0.CO;2-I

  39. [49]

    Asteroseismic signatures of stellar magnetic activity cycles

    Metcalfe TS, Dziembowski WA, Judge PG, Snow M. Asteroseismic signatures of stellar magnetic activity cycles. Mon. Notices R. Astron. Soc. 379 (2007) L16–L20. doi:10.1111/j.1745-3933.2007. 00325.x

  40. [50]

    Rotation, convection, and magnetic activity in lower main-sequence stars

    Noyes RW, Hartmann LW, Baliunas SL, Duncan DK, Vaughan AH. Rotation, convection, and magnetic activity in lower main-sequence stars. Astrophys. J. 279 (1984) 763–777. doi:10.1086/161945

  41. [51]

    Relation of Chromospheric Activity to Convection, Rotation, and Pre–Main-Sequence Evolution

    Gilliland RL. Relation of Chromospheric Activity to Convection, Rotation, and Pre–Main-Sequence Evolution. Astrophys. J. 300 (1986) 339. doi:10.1086/163807

  42. [52]

    Theoretical values of convective turnover times and Rossby numbers for solar-like, pre-main sequence stars

    Landin NR, Mendes LTS, Vaz LPR. Theoretical values of convective turnover times and Rossby numbers for solar-like, pre-main sequence stars. Astron. Astrophys. 510 (2010) A46. doi:10.1051/ 0004-6361/200913015

  43. [53]

    Time Scales for CaII Emission Decay, Rotational Braking, and Lithium Depletion

    Skumanich A. Time Scales for CaII Emission Decay, Rotational Braking, and Lithium Depletion. Astrophys. J. 171 (1972) 565–567. doi:10.1086/151310

  44. [54]

    Solar cycle induced variations of the low L solar acoustic spectrum

    Palle PL, Regulo C, Roca Cortes T. Solar cycle induced variations of the low L solar acoustic spectrum. Astron. Astrophys. 224 (1989) 253–258

  45. [55]

    Solar p-Mode Frequencies over Three Solar Cycles

    Chaplin WJ, Elsworth Y , Miller BA, Verner GA, New R. Solar p-Mode Frequencies over Three Solar Cycles. Astrophys. J. 659 (2007) 1749–1760. doi:10.1086/512543

  46. [56]

    sunstardb: A Database for the Study of Stellar Magnetism and the Solar-stellar Connection

    Egeland R. sunstardb: A Database for the Study of Stellar Magnetism and the Solar-stellar Connection. Astrophys. J. Suppl. Series 236 (2018) 19. doi:10.3847/1538-4365/aab771

  47. [57]

    Sounding stellar cycles with Kepler - I

    Karoff C, Metcalfe TS, Chaplin WJ, Elsworth Y , Kjeldsen H, Arentoft T, et al. Sounding stellar cycles with Kepler - I. Strategy for selecting targets. Mon. Notices R. Astron. Soc. 399 (2009) 914–923. doi:10.1111/j.1365-2966.2009.15323.x

  48. [58]

    Asteroseismic Fundamental Properties of Solar-type Stars Observed by the NASA Kepler Mission

    Chaplin WJ, Basu S, Huber D, Serenelli A, Casagrande L, Silva Aguirre V , et al. Asteroseismic Fundamental Properties of Solar-type Stars Observed by the NASA Kepler Mission. Astrophys. J. Suppl. Series 210 (2014) 1. doi:10.1088/0067-0049/210/1/1

  49. [59]

    Significantly improving stellar mass and radius estimates: a new reference function for the ∆ν scaling relation

    Guggenberger E, Hekker S, Basu S, Bellinger E. Significantly improving stellar mass and radius estimates: a new reference function for the ∆ν scaling relation. Mon. Notices R. Astron. Soc. 460 (2016) 4277–4281. doi:10.1093/mnras/stw1326

  50. [60]

    Testing the Asteroseismic Scaling Relations for Red Giants with Eclipsing Binaries Observed by Kepler

    Gaulme P, McKeever J, Jackiewicz J, Rawls ML, Corsaro E, Mosser B, et al. Testing the Asteroseismic Scaling Relations for Red Giants with Eclipsing Binaries Observed by Kepler. Astrophys. J. 832 (2016) 121. doi:10.3847/0004-637X/832/2/121

  51. [61]

    Influence of magnetic activity on the determination of stellar parameters through asteroseismology

    P´erez Hern´andez F, Garc´ıa RA, Mathur S, Santos ARG, R´egulo C. Influence of magnetic activity on the determination of stellar parameters through asteroseismology. Frontiers in Astronomy and Space Sciences 6 (2019) 41. doi:10.3389/fspas.2019.00041

  52. [62]

    Revised Stellar Properties of Kepler Targets for the Quarter 1-16 Transit Detection Run

    Huber D, Silva Aguirre V , Matthews JM, Pinsonneault MH, Gaidos E, Garc´ıa RA, et al. Revised Stellar Properties of Kepler Targets for the Quarter 1-16 Transit Detection Run. Astrophys. J. Suppl. Series 211 (2014) 2. doi:10.1088/0067-0049/211/1/2. Frontiers 21 Kiefer et al. Se...

  53. [63]

    Asteroseismology of 16,000 Kepler Red Giants: Global Oscillation Parameters, Masses, and Radii

    Yu J, Huber D, Bedding TR, Stello D, Hon M, Murphy SJ, et al. Asteroseismology of 16,000 Kepler Red Giants: Global Oscillation Parameters, Masses, and Radii. Astrophys. J. Suppl. Series 236 (2018)

  54. [64]

    doi:10.3847/1538-4365/aaaf74

  55. [65]

    Asteroseismic detection of latitudinal differential rotation in 13 Sun-like stars

    Benomar O, Bazot M, Nielsen MB, Gizon L, Sekii T, Takata M, et al. Asteroseismic detection of latitudinal differential rotation in 13 Sun-like stars. Science 361 (2018) 1231–1234. doi:10.1126/ science.aao6571

  56. [66]

    The Influence of Metallicity on Stellar Differential Rotation and Magnetic Activity

    Karoff C, Metcalfe TS, Santos ˆARG, Montet BT, Isaacson H, Witzke V , et al. The Influence of Metallicity on Stellar Differential Rotation and Magnetic Activity. Astrophys. J. 852 (2018) 46. doi:10.3847/1538-4357/aaa026

  57. [67]

    Sounding stellar cycles with Kepler - II

    Karoff C, Metcalfe TS, Chaplin WJ, Frandsen S, Grundahl F, Kjeldsen H, et al. Sounding stellar cycles with Kepler - II. Ground-based observations. Mon. Notices R. Astron. Soc. 433 (2013) 3227–3238. doi:10.1093/mnras/stt964

  58. [68]

    Evidence for photometric activity cycles in 3203 Kepler stars

    Reinhold T, Cameron RH, Gizon L. Evidence for photometric activity cycles in 3203 Kepler stars. Astron. Astrophys. 603 (2017) A52. doi:10.1051/0004-6361/201730599

  59. [69]

    The PLATO 2.0 mission

    Rauer H, Catala C, Aerts C, Appourchaux T, Benz W, Brandeker A, et al. The PLATO 2.0 mission. Experimental Astronomy 38 (2014) 249–330. doi:10.1007/s10686-014-9383-4. This is a provisional file, not the final typeset article 22 Kiefer et al. Seismic Signatures of Stellar Magneti...

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