LEMOULT , T.

Context. RRab stars are large amplitude pulsating stars in which the pulsation wave is a progressive wave. Consequently, strong shocks, stratification effects, and phase lag may exist between the variations associated with line profiles formed in different parts of the atmosphere, including the shock wake. The pulsation is associated with a...

Context. The so-called Hα third emission occurs around pulsation phase ϕ = 0.30. It has been observed for the first time in 2011 in some RR Lyrae stars. The emission intensity is very weak, and its profile is a tiny persistent hump in the red side-line profile.Aims. We report the first observation of the Hα third emission in RR Lyr itself...