We have modelled the X-ray emission of T Tauri stars assuming that they have isothermal, magnetically-confined coronae. These coronae extend outwards until either the pressure of the hot coronal gas overcomes the magnetic field, or, if the corona interacts with a disk before this happens, by the action of the disk itself. This work is motivated by the results of the Chandra Orion Ultradeep Proj...

Recent Visual and Infrared Thermal Imaging Spectrometer (VIRTIS) images from the Ve-nus Express mission found emissivity variations on the venusian surface that correlate with some volcanic edifices and coronae [1-3]. Increased emissivity was noted near Quet-zalpetlatl Coronae, Atete Corona, Mertseger Mons, Shiwanokia and Shulamite Coronae in Themis Regio, Idunn Mons, Hathor Mons and Ininni Mon...

There is increasing evidence of prominence-like neutral hydrogen clouds suspended in the otherwise hot coronae of active late-type stars. We review this evidence here and discuss the nature of these clouds. In particular we discuss their possible role in rotational braking.

Chandra Low Energy Transmission Grating Spectrograph observations of Algol have been used to determine the abundances of C and N in the secondary star for the first time. In order to minimise errors arising from an uncertain coronal differential emission measure as a function of temperature, the analysis was performed relative to similar observations of an adopted “standard” star HR 1099. It is...