Related papers: Variable magnetic field geometry of the young sun …
We aim to evaluate how well the variation of small-scale magnetic fields on the stellar surface can be monitored with time-series observations. Further, we aim to establish to what extent the measured total unsigned magnetic field traces…
The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small number of cool stars magnetic field topologies were…
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…
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…
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…
We report in this paper phase-resolved spectropolarimetric observations of the rapidly-rotating fully-convective M4 dwarf V374 Peg, on which a strong, mainly axisymmetric, large-scale poloidal magnetic field was recently detected. In…
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…
By studying young magnetically active late-type stars, i.e. analogues to the young Sun, one can draw conclusions on the evolution of the solar dynamo. We determine the topology of the surface magnetic field and study the relation between…
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 in this paper the first results of a spectropolarimetric analysis of a small sample (~ 20) of active stars ranging from spectral type M0 to M8, which are either fully-convective or possess a very small radiative core. This study…
Aims. The very weak magnetic field detected at the surface of Vega hints at a widespread population of weakly magnetic stars of A and B spectral types. We contribute here to gather more clues about the origin of this magnetism by…
Monitoring magnetic and activity variations in A- and B-type stars with ultra-weak magnetic fields is essential to understand the origin and evolution of these fields in this region of the HR diagram, with Vega standing as the prototype of…
The young and magnetically active K dwarf Epsilon Eridani exhibits a chromospheric activity cycle of about 3 years. Previous reconstructions of its large-scale magnetic field show strong variations at yearly epochs. To understand how…
Spectroscopic and spectropolarimetric observations of the pre-main sequence early-G star HD 141943 were obtained at four observing epochs (in 2006, 2007, 2009 and 2010). The observations were undertaken at the 3.9-m Anglo-Australian…
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…
Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric $\log{R^{\prime}_{\rm{HK}}}$ activity and the surface-averaged longitudinal magnetic field, $B_l$, giving the opportunity to probe the relationship between…
The recent discovery of a weak surface magnetic field on the normal intermediate-mass star Vega raises the question of the origin of this magnetism in a class of stars that was not known to host magnetic fields. We aim to confirm the field…
The surface rotation rates of young solar-type stars decrease rapidly with age from the end of the pre-main sequence though the early main sequence. This suggests that there is also an important change in the dynamos operating in these…
Variations of the weak magnetic fields of the photosphere with periods of the order of the solar magnetic cycle were investigated. Synoptic maps of the photospheric magnetic field produced by NSO Kitt Peak for the period from 1978 to 2016…