201 citations · 1.1k across the 38 of their papers we have counts for
38 papers
The origins of the magnetic field in tip-RGB, AGB and post-AGB stars
Renada Konstantinova-Antova, Stefan Georgiev, Agnès Lèbre +3
During the last decade and a half, the new generation spectropolarimeter Narval at Pic du Midi, France allowed the study of weak magnetic fields in cool giant stars that are fairly…
A long-term study of the magnetic field and activity in the M giant RZ Ari
R. Konstantinova-Antova, S. Georgiev, A. Lèbre +12
We present a detailed long-term study of the single M6 III giant RZ~Ari to obtain direct and simultaneous measurements of the magnetic field, activity indicators, and radial veloci…
Surface magnetism in the pulsating RV Tauri star R Scuti
Stefan Georgiev, Agnès Lèbre, Eric Josselin +3
We present the surface magnetic field conditions of the brightest pulsating RV Tauri star, R Sct. Our investigation is based on the longest spectropolarimetric survey ever performe…
Three-dimensional imaging of convective cells in the photosphere of Betelgeuse
A. López Ariste, S. Georgiev, Ph. Mathias +5
Understanding convection in red supergiants and the mechanisms that trigger the mass loss from these evolved stars are the general goals of most observations of Betelgeuse and its…
Determining rotational and macroturbulent velocities of cool magnetic giant stars
Stefan Georgiev, Agnès Lèbre, Eric Josselin +2
An original method of estimating the projected rotational velocity, , and the macroturbulent velocity, , of evolved M giant stars is presented. It is based on t…
A Long-Term Spectral Study of the Single Active Giant OP Andromedae
Stefan Georgiev, Renada Konstantinova-Antova, Ana Borisova +10
We present a spectral study of the single magnetically active K giant OP And in the period 1979 -- 2018, monitoring the variability of the activity indicator line H. Original da…