The propagation of a shock wave in a magnetic flux tube is studied within the framework of the Brinkley-Kirkwood theory adapted to a radiating gas. Simplified thermodynamic paths along which the compressed plasma returns to its initial state are considered. It is assumed that the undisturbed medium is uniform and that the flux tube is optically

We have performed a spectropolarimetric survey of the variable Mira star omicron Ceti along three pulsation cycles. We present those new data collected with the Narval instrument mounted on the Telescope Bernard Lyot (TBL) in Pic du Midi, France. We have detected time variable polarimetric signatures (on QUV Stokes spectra) associated with Balmer

The composition of the most primitive solar system condensates, such as calcium-aluminum-rich inclusions (CAIs) and micron-sized corundum grains, show that short-lived radionuclides (SLR), e.g., 26Al, were present in the early solar system. Their abundances require a local or stellar origin, which, however, is far from being understood. We present

I n the first decade of t h e 21 st cent u ry , the Egyptian - Spani sh Mission on Arc h a eoastronomy of ancient Egypt performed a detailed sta tistica l analysis of the orientation patterns of the temple s of Pharaonic Egypt , resulting in most interesting outcomes such as t h e justified proposal of seven families of astronomical orientations

Aims: We investigate the properties of a sunspot light bridge, focusing on the changes produced by the impact of a plasma blob ejected from a C-class flare. Methods: We observed a sunspot in active region NOAA 12544 using spectropolarimetric raster maps of the four Fe I lines around 15 655 Å with the GREGOR Infrared Spectrograph, narrow-band

Vulcanism was first detected on Io in 1978 by Voyager 1. Since then it has been recognised that Io is the most volcanically active body in the Solar System. Although the initial volcanic activity observed was in the form of SO[2] geysers and sulphur lakes, the Galileo mission has detected temperatures as high as 1800K on the surface, far in excess