Aims:We investigate the mass function in the substellar domain down to a few Jupiter masses in the young σ Orionis open cluster (3±2 Ma, d = 360^+70_-60 pc). Methods: We have performed a deep IJ-band search, covering an area of 790 arcmin2 close to the cluster centre. This survey was complemented with an infrared follow-up in the HK_s- and Spitzer

We review different surveys, in the optical and infrared, conducted in the very young (age 1 8 Myr), nearby (d ˜ 350 pc) σ Orionis cluster aimed to characterize the substellar population. We describe spectral characteristics of very low mass stars, brown dwarfs and planetary mass objects in the cluster with spectral types from K7 to T6. We study

The Sunrise balloon-borne solar observatory consists of a 1m aperture Gregory telescope, a UV filter imager, an imaging vector polarimeter, an image stabilization system and further infrastructure. The first science flight of Sunrise yielded high-quality data that reveal the structure, dynamics and evolution of solar convection, oscillations and

Asteroid dynamical families are supposed to be formed from the collisional disruption of parent bodies. As a consequence, the investigation of the surface properties of small and large family members may give some hints on the nature of the dynamical group, the internal composition of the parent body, and the role played by space weathering

K-band galaxy number counts (GNCs) exhibit a slope change at K ˜ 17.5 mag not present in optical bands. To unveil the nature of this feature, we have derived the contribution of different galaxy types to the total K-band GNCs at 0.3 < z < 1.5 by redshift bins and compared the results with expectations from several galaxy evolutionary models. We

We present a detailed chemical composition analysis of 35 red giant stars in the globular cluster M 22. High resolution spectra for this study were obtained at five observatories, and analyzed in a uniform manner. We have determined abundances of representative light proton-capture, α, Fe-peak and neutron-capture element groups. Our aim is to