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Mostrando ítems 41-50 de 2019
Magnetic activity and hot Jupiters of young Suns: the weak-line T Tauri stars V819 Tau and V830 Tau
(Oxford University Press, 2015)
We report results of a spectropolarimetric and photometric monitoring of the weak-line T Tauri stars (wTTSs) V819 Tau and V830 Tau within the MaTYSSE (Magnetic Topologies of Young Stars and the Survival of close-in giant ...
Stellar magnetism: empirical trends with age and rotation
(Royal Astronomic Society, 2014-02-28)
We investigate how the observed large-scale surface magnetic fields of low-mass stars (∼0.1–
2M ), reconstructed through Zeeman–Doppler imaging, vary with age t, rotation and Xray
emission. Our sample consists of 104 ...
Detection of a giant flare displaying quasi-periodic pulsations from a pre-main-sequence M star by the Next Generation Transit Survey
(Oxford University Press, 2019)
We present the detection of an energetic flare on the pre-main-sequence M3 star NGTS J121939.5–355557, which we estimate to be only 2 Myr old. The flare had an energy of 3.2 ±0 0 4 3 ×1036 erg and a fractional amplitude ...
SALT observations of the chromospheric activity of transiting planet hosts: Mass-loss and star-planet interactions
(Oxford University, 2017)
We measured the chromospheric activity of the four hot Jupiter hosts WASP-43, WASP-51/HAT-P-30, WASP-72 and WASP-103 to search for anomalous values caused by the close-in companions. The Mount Wilson CaIIH&KS-index was ...
Interplay of tidal evolution and stellar wind braking in the rotation of stars hosting massive close-in planets
(The American Astronomical Society, 2020)
Active Luminous Blue Variables in the Large Magellanic Cloud
(IOP Publishing, 2017-07)
We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three ...
Gamma-ray emission from massive stars interacting with active galactic nuclei jets
(Oxford University Press, 2013-10)
Dense populations of stars surround the nuclear regions of galaxies. In active galactic nuclei, these stars can interact with the relativistic jets launched by the supermassive black hole. In this work, we study the ...
The rotation - Lithium depletion correlation in the beta Pictoris association and LDB age determination
(EDP Sciences, 2016-11)
There is evidence in the 125-Myr Pleiades cluster, and more recently in the 5-Myr NGC 2264 cluster, that rotation plays a key role in the Lithium (Li) depletion processes among low-mass stars. Fast rotators appear to be ...
Ross 128-GL 447: A possible activity cycle for a slow-rotating fully convective star
(EDP Sciences, 2019-08)
Context. Long-term chromospheric activity in slow-rotating fully convective stars has scarcely been explored. Ross 128 (Gl 447) is a slow-rotator and inactive dM4 star that has been extensively observed. It hosts the fourth ...