We computed chromospheric models of the Sun as a star and of nine solar analogues. The atmospheric models were constructed to obtain the best possible match with the Ca II K and Hβ lines, including the asymmetry of the ...

We present a complete atomic model for Si I line synthesis. We study how the computed profiles of two blue lines of this atom are influenced by the choice of the atomic parameters and find that, although several cross ...

We study the chromospheric structure of a small flare, before, during and after the first hard X-ray spike. We construct 5 semiempirical models for different times, which will reproduce the profiles of the Hδ, Ca II K and ...

We have built different models for stars of the same spectral type than the Sun but with different levels of chromospheric activity, to study the response of the S index of activity built from the emission of the Ca II ...

As part of an ongoing project to study how reliable are the chromospheric models constructed semiempirically to fit the chromospheric spectrum of cold stars, in this paper we study how changes in the assumed chromospheric ...

In this study we test the possibility that the asymmetry in the profiles of the Hα and Ca ii K lines in red giant stars is due to the presence of an active chromosphere rather than to mass loss. To this end, we compare ...

In this work we present chromospheric activity indices, kinematics, radial-velocities and rotational velocities for more than 850 FGK-type dwarfs and subgiant stars in the southern hemisphere and test how best to calibrate ...

Stellar radiation from X-rays to the visible provides the energy thatcontrols the photochemistry and mass loss from exoplanet atmospheres.The important extreme ultraviolet (EUV) region (10-91.2 nm) isinaccessible and should ...

We examine the capability of a blast-wave scenario - associated with a coronal flare or to the expansion of CME flanks - to reproduce a chromospheric Moreton phenomenon. We also simulate the Moreton event of 2006 December ...