Amplitudes of Solar Gravity Modes: A Review

Belkacem, K.; Pinçon, C.; Buldgen, G.

doi:10.1007/s11207-022-02075-5

Cited by 4 publications

(3 citation statements)

References 95 publications

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“…The uncertainties on the p-mode splittings were estimated to be the same as those of the oscillation modes themselves, in the exception of two regimes: the low-l, low-n frequencies for which the actual uncertainties from Davies et al (2014) were used, as well as for the low-l high-n frequencies, for which the uncertainties and modes considered in the set were estimated from Mathur et al (2008). The gmode splittings were generated in the same way, considering modes around 100 µHz that have the highest detection probability according to recent theoretical estimates (Pinçon, Appourchaux, and Buldgen, 2021;Belkacem, Pinçon, Buldgen, 2022) using uncertainties estimated to range from 13 to 1 µHz for modes from around 160 µHz to 38 µ Hz. Tests were attempted with 10 and 20 g-modes, considering only the highest-frequency range in the reduced set.…”

Section: An Example Solar Core Rotation Inversion With Artificial Datamentioning

confidence: 99%

Probing the Structure and Dynamics of the Solar Core with Gravity Modes

Leibacher,

Appourchaux,

Buldgen

et al. 2023

Bulletin of the AAS

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Section: An Example Solar Core Rotation Inversion With Artificial Datamentioning

confidence: 99%

Probing the Structure and Dynamics of the Solar Core with Gravity Modes

Leibacher,

Appourchaux,

Buldgen

et al. 2023

Bulletin of the AAS

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“…This information is still missing in the landscape of stellar physics (e.g. Appourchaux & Pallé 2013;Belkacem et al 2022). In particular, Mathur et al (2014a) suggested that the long-term stability of the photometric rotational modulation observed in F-type stars could result from the existence of active longitudes in the photosphere of these stars, while Mittag et al (2019) speculated that their activity cycle could be shorter and of different nature than those of cooler solar analogues.…”

Section: Introductionmentioning

confidence: 99%

Tracking active nests in solar-type pulsators: Ensemble starspot modelling of Kepler asteroseismic targets

Breton,

Lanza,

Messina

2024

A&A

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The satellite Planetary Transits and Oscillations of stars (PLATO), due to be launched late 2026, will provide us with an unprecedented sample of light curves of solar-type stars that will exhibit both solar-type oscillations and signatures of activity-induced brightness modulations. Solar-type pulsators only have moderate levels of activity because high levels of activity inhibit oscillations. This means that these targets represent a specific challenge for starspot modelling. In order to assess the possibilities that PLATO will soon open, we wish to characterise the morphology of active regions at the surface of stars for which we also have a detection of solar-like acoustic oscillations. In this context, we report the results of an ensemble starspot modelling analysis of the Sun and ten solar-type pulsators observed by the Kepler satellite. We implement a Bayesian starspot modelling approach based on a continuous-grid model, accounting for the combined starspot and facular contribution to activity-induced brightness modulations. From our analysis, we find that several stars of our sample exhibit clear signatures of stable longitudinal active nests while sharing activity levels and convection versus rotation regimes similar to the solar regime. By searching for modulations in the reconstructed starspot coverage, we found significant periodicities that we identify as possible signatures of cyclic modulations similar to the quasi-biennal oscillation or the Rieger cycle. We can infer the corresponding intensity of the magnetic field at the bottom of the convective envelope based on the hypothesis that internal magneto-Rossby waves acting on the tachocline cause these modulations.

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“…For an extensive review and discussion of these two claims and the history of the search of solar g modes, we refer the reader toAppourchaux & Pallé (2013), Sect. 1 fromBreton et al (2022a), andBelkacem et al (2022).…”

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confidence: 99%

In search of gravity mode signatures in main sequence solar-type stars observed by Kepler

Breton,

Dhouib,

García

et al. 2023

A&A

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Gravity modes (g modes), mixed gravito-acoustic modes (mixed modes), and gravito-inertial modes (gi modes) possess unmatched properties as probes for stars with radiative interiors. The structural and dynamical constraints that they are able to provide cannot be accessed by other means. While they provide precious insights into the internal dynamics of evolved stars as well as massive and intermediate-mass stars, their non-detection in main sequence (MS) solar-type stars make them a crucial missing piece in our understanding of angular momentum transport in radiative zones and stellar rotational evolution. In this work, we aim to apply certain analysis tools originally developed for helioseismology in order to look for g-mode signatures in MS solar-type stars. We select a sample of the 34 most promising MS solar-type stars with Kepler four-year long photometric time series. All these stars are well-characterised late F-type stars with thin convective envelopes, fast convective flows, and stochastically excited acoustic modes (p modes). For each star, we compute the background noise level of the Fourier power spectrum to identify significant peaks at low frequency. After successfully detecting individual peaks in 12 targets, we further analyse four of them and observe distinct patterns of surrounding peaks with a low probability of being noise artifacts. Comparisons with the predictions from reference models suggest that these patterns are compatible with the presence of non-asymptotic low-order pure g modes, pure p modes, and mixed modes. Given their sensitivity to both the convective core interface stratification and the coupling between p- and g-mode resonant cavities, such modes are able to provide strong constraints on the structure and evolutionary states of the related targets. Considering the granulation and activity background of the stars in our sample, we subsequently compute the corresponding mode velocity necessary to trigger a detectable luminosity fluctuation. We use it to estimate the surface velocity, ⟨vr⟩, of the candidate modes we have detected. In this case, we find ⟨vr⟩∼10 cm s−1. These results could be extremely useful for characterising the deep interior of MS solar-type stars, as the upcoming PLATO mission will considerably expand the size of the available working sample.

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Amplitudes of Solar Gravity Modes: A Review

Cited by 4 publications

References 95 publications

Probing the Structure and Dynamics of the Solar Core with Gravity Modes

Probing the Structure and Dynamics of the Solar Core with Gravity Modes

Tracking active nests in solar-type pulsators: Ensemble starspot modelling of Kepler asteroseismic targets

In search of gravity mode signatures in main sequence solar-type stars observed by Kepler

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