The Fine Structure of the Quasi-Biennial Oscillations of Sunspot Areas and the Double Magnetic Cycle of the Sun

Kostyuchenko, I.G.; Бруевич, Е. А.

doi:10.1007/s11207-020-01745-6

Cited by 3 publications

(3 citation statements)

References 37 publications

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“…Around the maxima of the two cycles, modulations at lower frequencies are visible between 500 and 1500 days and can be interpreted as the manifestation of the quasi-biennal oscillation in sunspot coverage (e.g. Kostyuchenko & Bruevich 2021). The reconstructed spot coverage exhibits similar features, although some discrepancies are also visible.…”

Section: A Difficult Case With Ground Truth: the Sunmentioning

confidence: 92%

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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Section: A Difficult Case With Ground Truth: the Sunmentioning

confidence: 92%

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

Breton,

Lanza,

Messina

2024

A&A

View full text Add to dashboard Cite

show abstract

“…In addition, the featured coronal holes and sunspots determine the solar cycle and the three-dimensional (3D) heliospheric magnetic configuration that establishes the Sun-heliosphere connection. In this respect, within this collection, fundamental investigations have been performed to understand the solar atmosphere plasma thermodynamics, magnetic field configuration, and long-term variations (Lloveras et al, 2020;Ryabov and Vrublevskis, 2020;Kostyuchenko and Bruevich, 2021;Nandy, 2021). Lloveras et al (2020) carried out, compared, and reported a detailed study of the global 3D structure of the electron density and temperature of the quiescent inner solar corona based on the differential emission measure tomography (DEMT) and the Alfvén Wave Solar Model (AWSoM) in their latest versions.…”

mentioning

confidence: 99%

“…This is another noteworthy contribution to this TC. In the study carried out by Kostyuchenko and Bruevich (2021), the authors focused on the fine structure of quasi-biennal oscillations (QBOs) of the sunspot areas during Solar Cycles 19 -23. The QBO period gradually decreases from the beginning of the solar cycle till the end in phase with the shift of the average latitudes of sunspots to the equator: a scenario of this behavior within the convection zone is proposed.…”

mentioning

confidence: 99%