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Related papers: Investigating stellar activity with CoRoT data and…

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B-type stars are promising targets for asteroseismic modelling, since their frequency spectrum is relatively simple. We deduce and summarise observational constraints for the hybrid pulsator, HD50230, earlier reported to have deviations…

We introduce a framework to measure the asphericity of Sun-like stars using $a_1$, $a_2$ and $a_4$ coefficients, and constrain their latitudes of magnetic activity. Systematic errors on the inferred coefficients are evaluated in function of…

Solar and Stellar Astrophysics · Physics 2023-12-13 Othman Benomar , Masao Takata , Michael Bazot , Takashi Sekii , Laurent Gizon , Yuting Lu

Context : On its asteroseismic side, the initial run of CoRoT was partly devoted to the solar like star HD49933.The eigenmodes of this F dwarf have been observed with unprecedented accuracy. Aims : We investigate quantitatively the impact…

Solar and Stellar Astrophysics · Physics 2015-05-13 L. Piau , S. Turck-Chieze , V. Duez , R. F. Stein

It is believed that magnetic activity on the Sun and solar-type stars are tightly related to the dynamo process driven by the interaction between rotation, convection, and magnetic field. However, the detailed mechanisms of this process are…

Solar and Stellar Astrophysics · Physics 2017-03-08 S. Mathur

We present results obtained from the studies of magnetic activities on four solar-type stars (F-type star KIC 6791060, K-type star LO Peg, and two M-type planet-hosting stars K2-33 and EPIC 211901114) by using optical observations from…

Solar and Stellar Astrophysics · Physics 2019-06-03 Subhajeet Karmakar , Jeewan C. Pandey , Sachindra Naik , Igor S. Savanov , Ashish Raj

The photometric time series of solar-like stars can exhibit rotational modulation due to active regions co-rotating with the stellar surface, allowing us to constrain stellar rotation and magnetic activity. In this work we investigate the…

Our knowledge of magnetic activity of stars is mostly based on the study of the Sun and some spectroscopic surveys of a few hundreds of stars. However, the detailed mechanisms of the solar magnetic activity cycle are not fully understood.…

Solar and Stellar Astrophysics · Physics 2013-08-06 S. Mathur

Rotation is thought to drive cyclic magnetic activity in the Sun and Sun-like stars. Stellar dynamos, however, are poorly understood owing to the scarcity of observations of rotation and magnetic fields in stars. Here, inferences are drawn…

The photospheric spot activity of some of the stars with transiting planets discovered by the CoRoT space experiment is reviewed. Their out-of-transit light modulations are fitted by a spot model previously tested with the total solar…

Solar and Stellar Astrophysics · Physics 2015-05-20 A. F. Lanza

The Mount Wilson Ca HK survey revealed magnetic activity variations in a large sample of solar-type stars with timescales ranging from 2.5 to 25 years. This broad range of cycle periods is thought to reflect differences in the rotational…

Solar and Stellar Astrophysics · Physics 2010-11-03 T. S. Metcalfe , S. Basu , T. J. Henry , D. R. Soderblom , P. G. Judge , M. Knoelker , S. Mathur , M. Rempel

The known beta Cephei star HD 180642 was observed by the CoRoT satellite in 2007. From the very high-precision light curve, its pulsation frequency spectrum could be derived for the first time (Degroote and collaborators). In this paper, we…

Context. OB stars are important building blocks of the Universe, but we have only a limited sample of them well understood enough from an asteroseismological point of view to provide feedback on the current evolutionary models. Our study…

We present a dataset for investigating the impact of stellar activity on astrometric measurements using NASA's Solar Dynamics Observatory (SDO) images of the Sun. The sensitivity of astrometry for detecting exoplanets is limited by stellar…

Solar and Stellar Astrophysics · Physics 2023-10-20 Warit Wijitworasart , Zoe de Beurs , Andrew Vanderburg

The SRa02 of the CoRoT space mission for Asteroseismology was partly devoted to stars belonging to the Mon OB2 association. An intense monitoring was performed on Plaskett's Star (HD47129) and the unprecedented quality of the light curve…

Solar and Stellar Astrophysics · Physics 2015-05-20 L. Mahy , E. Gosset , F. Baudin , G. Rauw , M. Godart , T. Morel , P. Degroote , C. Aerts , R. Blomme , J. Cuypers , A. Noels , E. Michel , A. Baglin , M. Auvergne , C. Catala , R. Samadi

We focus on the influence of the Coriolis acceleration on the stochastic excitation of oscillation modes in convective regions of rotating stars. Our aim is to estimate the asymmetry between excitation rates of prograde and retrograde…

Solar and Stellar Astrophysics · Physics 2015-05-14 K. Belkacem , S. Mathis , M. J. Goupil , R. Samadi

The variability of H$\alpha$ chromospheric activity of solar-like stars is investigated by using the time-domain data of LAMOST Medium-Resolution Spectroscopic Survey (MRS). We use $R_\mathrm{H\alpha}$ index (ratio of H$\alpha$ luminosity…

Solar and Stellar Astrophysics · Physics 2025-12-10 Han He , Ali Luo , Haotong Zhang , Song Wang

Effective temperatures, surface gravities, and iron abundances were derived for 109 stars observed by the K2 mission using equivalent width measurements of Fe I and Fe II lines. Calculations were carried out in LTE using Kurucz model…

Solar and Stellar Astrophysics · Physics 2024-07-19 V. Loaiza-Tacuri , Katia Cunha , Verne V. Smith , F. Quispe-Huaynasi , Ellen Costa-Almeida , Luan Ghezzi , Jorge Melendez

The variations of the frequencies of the low-degree acoustic oscillations in the Sun induced by magnetic activity show a dependence with radial order. The frequency shifts are observed to increase towards higher-order modes to reach a…

Solar and Stellar Astrophysics · Physics 2018-04-04 D. Salabert , C. Régulo , F. Pérez Hernández , R. A. García

Evidence suggesting an observable magnetic interaction between a star and its hot Jupiter appears as a cyclic variation of stellar activity synchronized to the planet's orbit. In this study, we monitored the chromospheric activity of 7…

The magnetic fields, activity and dynamos of young solar-type stars can be empirically studied using time-series of spectropolarimetric observations and tomographic imaging techniques such as Doppler imaging and Zeeman Doppler imaging. In…