Summary: PROMINENCES ON LATE TYPE ACTIVE STARS
P.B. BYRNE
Armagh Observatory
Armagh BT61 9DG, N. Ireland
Abstract. There is increasing evidence of prominence­like neutral hydro­
gen clouds suspended in the otherwise hot coronae of active late­type stars.
We review this evidence here and discuss the nature of these clouds. In
particular we discuss their possible role in rotational braking.
1. Introduction
The solar paradigm is widely used to explain a broad range of phenomena on
late­type stars. These include stellar flares, sudden brightenings in broad­
band radiation, from microwaves to hard X­rays (analogous to solar flares),
modulation of global visible and near­IR light by the varying visibility of
dark areas on the stellar surface as the underlying star rotates (``starspots'',
analogous to sunspots), and non­radiative heating of hot chromospheres
and coronae. All of these phenomena arise from powerful magnetic fields,
generated by the interaction of differential rotation and deep convection,
and intensified locally into loop structures at the photosphere and above,
in a manner familiar on the Sun.
Studying stellar counterparts of solar magnetic activity offers us many

Source: Armagh Observatory

Collections: Physics