We have discovered small whirlpools in the Sun, with a size similar to terrestrial hurricanes (

Aims: Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble far ultraviolet observations, we aim to detect and identify the faint X-ray sources belonging to the Galactic globular cluster NGC 2808 in order to understand their role in the evolution of globular clusters. Methods: We present a Chandra X-ray observation of the

Context: The connection of cluster mergers with the presence of extended, diffuse radio sources in galaxy clusters is still debated. An interesting case is the rich, merging cluster Abell 520, containing a radio halo. A recent gravitational analysis has shown in this cluster the presence of a massive dark core suggested to be a possible problem for

Context: The young σ Orionis cluster is an important location for studying the formation and evolution of stars, brown dwarfs, and planetary-mass objects. Its metallicity, although it is a fundamental parameter, has not been well determined yet. Aims: We present the first determination of the metallicity of nine young late-type stars in σ Orionis

The accreting millisecond X-ray pulsar SAX J1808.4-3658 recently exhibited another outburst in September and October 2008 (ATel #1728). During this outburst, on 2008 Oct 2, we obtained a ~40 ks observation with Suzaku. The XIS detectors were operated in 1/4 window mode, with 1 sec burst, leading to a good time exposure of 21 ks for the XIS 0, 1 and

Context: Current atmospheric models cannot reproduce some of the characteristics of the transition between the L dwarfs with cloudy atmospheres and the T dwarfs with dust-depleted photospheres. It has been proposed that a majority of the L/T transition brown dwarfs could actually be a combinaison of a cloudy L dwarf and a clear T dwarf. Indeed