Simulations have shown that a diverse range of extrasolar terrestrial planet bulk compositions are likely to exist based on the observed variations in host star elemental abundances. Based on recent studies, it is expected that a significant proportion of host stars may have Mg/Si ratios below 1. Here we examine this previously neglected group of

Context. The Centaurs are a transitional population of minor bodies of the solar system and the evolutionary link between the trans-Neptunian objects and the short period comets. The surface properties of these objects are very peculiar, because currently available data suggest that their visual surface colors divide the population into two

We present visible wavelength photometry of the OSIRIS-REx target asteroid (101955) 1999 RQ36. We find a rotation period of 4.2968 ± 0.0017 hr and phase slope of 0.039 mag/deg. YORP induced rotation rate changes should be detectable by OSIRIS-REx.

Context. Full Stokes filter-polarimeters are key instruments for investigating the rapid evolution of magnetic structures on the solar surface. To this end, the image quality is routinely improved using a-posteriori image reconstruction methods. Aims: We analyze the robustness of circular polarization asymmetries to phase-diversity image

Aims: With available Virtual Observatory tools, we looked for new M dwarfs in the solar neighbourhood and M giants with high tangential velocities. Methods: From an all-sky cross-match between the optical Tycho-2 and the near-infrared 2MASS catalogues, we selected objects with proper motions μ > 50 mas yr-1 and very red VT - Ks colours. For the

We identify HS 2325+8205 as an eclipsing, frequently outbursting, dwarf nova with an orbital period of Porb = 279.841731(5) minutes. Spectroscopic observations are used to derive the radial velocity curve of the secondary star from absorption features and also from the Hα emission lines, originating from the accretion disk, yielding Ksec = Kabs =