Two new late-type L subdwarfs were discovered in our recent search of UKIDSS and SDSS. We discuss the signatures of halo brown dwarfs based on known and new L subdwarfs. These indicate that the halo stellar/substellar T_eff gap is likely between esdL4 and esdL6.

We present preliminary results of a brown dwarf (BD) detection in a ˜1000 star sample monitored with the ongoing PennState-Toruń Centre for Astronomy Planet Search. Contrary to most other projects, our sample contains a substantial fraction of evolved stars ranging from sub-giants up to bright giants, allowing us to study companions to stars more

In the last two decades, solar physics has greatly explored the 10^-3 polarimetric sensitivity level (referred to the continuum intensity). This has provided us with a quantitatively accurate picture of the photospheric magnetism for mean longitudinal fields in the range of about 5 Gauss. However, the same 10^-3 detection levels translate into a

We present the Data Release 9 Quasar (DR9Q) catalog from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III. The catalog includes all BOSS objects that were targeted as quasar candidates during the survey, are spectrocopically confirmed as quasars via visual inspection, have luminosities Mi[z = 2] -20.5 (in a

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z ~ 0.52), 102,100 new quasar spectra (median z ~ 2.32), and 90,897 new stellar spectra, along with the data

The effects that interactions produce on galaxy disks and how they modify the subsequent formation of bars need to be distinguished to fully understand the relationship between bars and environment. To this aim we derive the bar fraction in three different environments ranging from the field to Virgo and Coma Clusters, covering an unprecedentedly