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Related papers: Revisiting the correlation between stellar activit…

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In this splinter session, ten speakers presented results on solar and stellar activity and how the two fields are connected. This was followed by a lively discussion and supplemented by short, one-minute highlight talks. The talks presented…

Solar and Stellar Astrophysics · Physics 2014-08-14 H. M. Günther , K. Poppenhaeger , P. Testa , S. Borgniet , S. Brun , H. Cegla , C. Garraffo , A. Kowalski , A. Shapiro , E. Shkolnik , F. Spada , A. Vidotto

We analyze the correlation between starspots and superflares on solar-type stars using observations from the Kepler mission. The analysis shows that the observed fraction of stars with superflares decreases as the rotation period increases…

Solar and Stellar Astrophysics · Physics 2017-06-21 Hiroyuki Maehara , Yuta Notsu , Shota Notsu , Kosuke Namekata , Satoshi Honda , Takako T. Ishii , Daisaku Nogami , Kazunari Shibata

We use photometric observations of solar-type stars, made by the NASA Kepler Mission, to conduct a statistical study of the impact of stellar surface activity on the detectability of solar-like oscillations. We find that the number of stars…

Context. Searching for extrasolar planets through radial velocity measurements relies on the stability of stellar photospheres. Aims. We aim at characterizing the statistical properties of magnetic activity cycles, and studying their impact…

Solar and Stellar Astrophysics · Physics 2011-07-28 C. Lovis , X. Dumusque , N. C. Santos , F. Bouchy , M. Mayor , F. Pepe , D. Queloz , D. Ségransan , S. Udry

We utilize Kepler data to study the precision differential photometric variability of solar-type and cooler stars at different timescales, ranging from half an hour to 3 months. We define a diagnostic that characterizes the median…

Solar and Stellar Astrophysics · Physics 2016-03-02 Gibor Basri , Lucianne Walkowicz , Ansgar Reiners

We need to establish a correspondence between the magnetic structures generated by models and usual stellar activity indexes to simulate radial velocity time series for stars less active than the Sun. This is necessary to compare the…

Solar and Stellar Astrophysics · Physics 2018-08-01 Nadège Meunier

We have acquired high-resolution echelle spectra of 225 F6-M5 type stars in the southern hemisphere. The stars are targets or candidates to be targets for the Anglo-Australian Planet Search. CaII HK line cores were used to derive activity…

Context. Signatures of chromospheric activity enhancement have been found for a dozen stars, pointing to a possible star-planet interaction. Nevertheless in the coronal activity regime, there is no conclusive observational evidence for such…

Earth and Planetary Astrophysics · Physics 2011-05-06 B. L. Canto Martins , M. L. das Chagas , S. Alves , I. C. Leão , L. P. de Souza Neto , J. R. de Medeiros

Context. To enable radial velocity (RV) precision on the order of ~0.1 m/s required for the detection of Earth-like exoplanets orbiting solar-type stars, the main obstacle lies in mitigating the impact of stellar activity. Aims. This study…

Solar and Stellar Astrophysics · Physics 2022-08-10 K. Al Moulla , X. Dumusque , M. Cretignier , Y. Zhao , J. A. Valenti

In this paper we propose a class of weighted rank correlation coefficients extending the Spearman's rho. The proposed class constructed by giving suitable weights to the distance between two sets of ranks to place more emphasis on items…

Statistics Theory · Mathematics 2020-01-22 M. Sanatgar , A. Dolati , M. Amini

The detection of exoplanets using any method is prone to confusion due to the intrinsic variability of the host star. We investigate the effect of cool starspots on the detectability of the exoplanets around solar-like stars using the…

Earth and Planetary Astrophysics · Physics 2015-06-23 H. Korhonen , J. M. Andersen , N. Piskunov , T. Hackman , D. Juncher , S. P. Jarvinen , U. G. Joergensen

Rapid rotation enhances the dynamo operating in stars, and thus also introducessignificantly stronger magnetic activity than is seen in slower rotators. Many young cool stars still have the rapid, primordial rotation rates induced by the…

Solar and Stellar Astrophysics · Physics 2015-06-03 H. Korhonen

In the present study, we investigate the multifractal nature of a long-cadence time series observed by the \textit{Kepler} mission for a sample of 34 M dwarf stars and the Sun in its active phase. Using the Multifractal Detrending Moving…

While the strong anti-correlation between chromospheric activity and age has led to the common use of the Ca II H & K emission index (R'_HK = L_HK/L_bol) as an empirical age estimator for solar type dwarfs, existing activity-age relations…

Astrophysics · Physics 2009-11-13 Eric E. Mamajek , Lynne A. Hillenbrand

We report the discovery of a new relationship between a simple morphological characteristic of light curves produced by starspots and stellar rotation periods. The characteristic we examine is whether the light curve exhibits one dip or two…

Solar and Stellar Astrophysics · Physics 2018-08-29 Gibor Basri , Hieu T. Nguyen

Previous research has established a relationship between radial action and scale height in Galactic disks, unveiling a correlation between radial and vertical heating. This finding poses a challenge to our existing comprehension of heating…

Astrophysics of Galaxies · Physics 2024-12-13 Yunpeng Jia , Chengqun Yang , Yuqin Chen , Cuihua Du , Gang Zhao

We present evidence for a correlation between the observed properties of hot Jupiter emission spectra and the activity levels of the host stars measured using Ca II H & K emission lines. We find that planets with dayside emission spectra…

Earth and Planetary Astrophysics · Physics 2015-05-18 Heather A. Knutson , Andrew W. Howard , Howard Isaacson

We have used two robotic telescopes to obtain time-series high-resolution spectroscopy and V I and/or by photometry for a sample of 60 active stars. Orbital solutions are presented for 26 SB2 and 19 SB1 systems with unprecedented phase…

Solar and Stellar Astrophysics · Physics 2015-06-11 K. G. Strassmeier , M. Weber , T. Granzer , S. Järvinen

Using the far-UV (FUV) and near-UV (NUV) photometry from the NASA Galaxy Evolution Explorer (GALEX), we searched for evidence of increased stellar activity due to tidal and/or magnetic star-planet interactions (SPI) in the 272 of known FGK…

Solar and Stellar Astrophysics · Physics 2015-06-12 Evgenya L. Shkolnik

Stellar activity is a potential important limitation to the detection of low mass extrasolar planets with indirect methods (RV, photometry, astrometry). In previous papers, using the Sun as a proxy, we investigated the impact of stellar…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. -M. Lagrange , N. Meunier , M. Desort , F. Malbet