相关论文: The relation between stellar magnetic field geomet…
During the last decade, the relation between activity cycle periods with stellar parameters has received special attention. The construction of reliable registries of activity reveals that solar type stars exhibit activity cycles with…
The active K2 dwarf epsilon Eri has been extensively characterized, both as a young solar analog and more recently as an exoplanet host star. As one of the nearest and brightest stars in the sky, it provides an unparalleled opportunity to…
Cool main-sequence stars, such as the Sun, have magnetic fields which are generated by an internal dynamo mechanism. In the Sun, the dynamo mechanism produces a balance between the amounts of magnetic flux generated and lost over the Sun's…
We report on observations of the active K2 dwarf $\epsilon$ Eridani based on contemporaneous SPIRou, NARVAL, and TESS data obtained over two months in late 2018, when the activity of the star was reported to be in a non-cyclic phase. We…
The long-term monitoring of magnetic cycles in cool stars is a key diagnostic in understanding how dynamo generation and amplification of magnetic fields occur in stars similar in structure to the Sun. We investigate the temporal evolution…
The behaviour of the large-scale dipolar field, during a star's magnetic cycle, can provide valuable insight into the stellar dynamo and associated magnetic field manifestations such as stellar winds. We investigate the temporal evolution…
In 2015 we started the XMM-Newton monitoring of the young solar-like star Epsilon Eridani (440 Myr), one of the youngest solar-like stars with a known chromospheric CaII cycle. By analyzing the most recent Mount Wilson S-index CaII data of…
$\epsilon$ Eridani is a highly active young K2 star with an activity cycle of about three years established using Ca II H & K line index measurements (S_MWO). This relatively short cycle has been demonstrated to be consistent with X-ray and…
Zeeman Doppler imaging has successfully mapped the large-scale magnetic fields of stars over a large range of spectral types, rotation periods and ages. When observed over multiple epochs, some stars show polarity reversals in their global…
We study the differences in chromospheric structure induced in K stars by stellar activity, to expand our previous work for G stars, including the Sun as a star. We selected six stars of spectral type K with 0.82$<B-V<$0.90, including the…
The large-scale magnetic field of solar-type stars reconstructed from their spectropolarimetric observations provide important insight into their underlying dynamo processes.We aim to investigate the temporal variability of the large-scale…
Planets orbiting young, solar-type stars are embedded in a more energetic environment than that of the solar neighbourhood. They experience harsher conditions due to enhanced stellar magnetic activity and wind shaping the secular evolution…
We present new magnetic field measurements of the K2 main-sequence star $\epsilon$ Eridani based on principal components analysis (PCA) line-profile reconstructions. The aim of this paper is to quantify the surface-averaged magnetic field…
One of the aims of the BCool programme is to search for cycles in other stars and to understand how similar they are to the Sun. In this paper we aim to monitor the evolution of $\tau$ Boo's large-scale magnetic field using high-cadence…
A detailed investigation of the magnetic properties of young Sun-like stars can provide valuable information on our Sun's magnetic past and its impact on the early Earth. We determine the properties of the moderately rotating young Sun-like…
We present a detailed determination of the astrophysical parameters of the chromospherically active binary star EI Eridani. Our new radial velocities allow to improve the set of orbital elements and reveal long-term variations of the…
Context. Young, solar analogue stars provide key insights into the early stages of stellar evolution, particularly in terms of magnetic activity and rotation. Their rapid rotation, high flaring rate, and enhanced surface activity make them…
Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three…
We use our photometric time series of more than forty years to analyze the long-term behaviour of EI Eri. Flare activity is investigated using space-borne photometric data obtained with TESS. The MUSICOS campaign aimed to achieve…
Asteroseismology can provide information that is otherwise not easily accessible, like the stellar mass and the evolutionary stage. Strong magnetic fields are usually accompanied by rapid rotation, which makes asteroseismology difficult due…