Related papers: Crossing into the substellar regime in Praesepe

We present a search for low-mass brown dwarfs in the Pleiades open cluster. The identification of Pleiades members fainter and cooler than those currently known allows us to constrain evolutionary models for L dwarfs and to extend the study…

We analyze very deep IRAC and MIPS photometry of $\sim$ 12,500 members of the 14 Myr old Double Cluster, h and $\chi$ Persei, building upon on our earlier, shallower Spitzer studies (Currie et al. 2007a, 2008a). Numerous likely members show…

We image 104 newly identified low-mass (mostly M-dwarf) pre-main sequence members of nearby young moving groups with Magellan Adaptive Optics (MagAO) and identify 27 binaries with instantaneous projected separation as small as 40 mas. 15…

Deep mid-infrared (MIR) observations could reveal a population of faint, high-redshift (z>3) dusty starburst galaxies that are the progenitors of present-day spheroids or bulges, and are beyond the reach of current instruments. We utilize a…

Extrasolar planet searches targeting very low-mass stars and brown dwarfs are hampered by intrinsic or instrumental limitations. Time series of astrometric measurements with precisions better than one milli-arcsecond can yield new evidence…

The ~800 optically unseen (R>25.5) 24mum-selected sources in the complete Spitzer First Look Survey sample (Fadda et al. 2006) with F[24mum]>0.35 mJy are found to be very strongly clustered. If, as indicated by several lines of…

We have obtained intermediate-resolution optical spectroscopy of 44 candidate very low mass members of the nearby young open cluster IC2391. Of these, 26 spectra are totally new, 14 were already analyzed in a previous paper and another four…

We investigate the rotation periods of fully convective very low mass stars (VLM, M<0.3 Msol), with the aim to derive empirical constraints for the spindown due to magnetically driven stellar winds. Our analysis is based on a new sample of…

We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared…

We present a study of the properties of the star-cluster systems around pseudo-bulges of late-type spiral galaxies using a sample of 11 galaxies with distances from 17 to 37 Mpc. Star clusters are identified from multiband HST ACS and WFPC2…

The aim of the project is to find the stars nearest to the Sun and to contribute to the completion of the stellar and substellar census of the solar neighbourhood. We identified a new late-M dwarf within 5 pc, looking for high proper motion…

The mass domain where massive extrasolar planets and brown dwarfs lay is still poorly understood. Indeed, not even a clear dividing line between massive planets and brown dwarfs has been established yet. This is partly due to the paucity of…

We describe our all-sky survey for >M4 candidate members to nearby, young associations from the 2MASS and WISE catalogs using bayesian inference. We report the first results, including 38 highly probable candidates showing spectroscopic…

We surveyed thirteen very low mass (VLM; M < 0.2 M_sun) objects in the Taurus star-forming region using near-infrared diffraction-limited imaging techniques on the W.M. Keck I 10 m telescope. Of these thirteen, five were found to be binary,…

We present new near-infrared spectroscopic observations of the outer edges of the young stellar cluster around the supermassive black hole at the Galactic center. The observations show a break in the surface-density profile of young stars…

We present the results of a HST WFPC2 search for substellar companions to members of the star-forming cluster IC 348. The detection limits for companions to low-mass stars and brown dwarfs in the PC images are dm_791=0, 2.5, and 5.5 at…

We present a deep I,Z photometric survey covering a total area of 1.12 deg^{2} of the Sigma Orionis cluster (Icompl=22 and Zcompl=21.5mag). From I, I-Z color-magnitude diagrams we have selected 153 candidates that fit the previously known…

We present the results of an optical multi-band survey for low-mass Pre-Main Sequence (PMS) stars and young Brown Dwarfs (BDs) in the Chamaeleon II (Cha II) dark cloud. This survey constitutes the complementary optical data to the c2d…

We aim at identifying very low-mass isolated planetary-mass member candidates in the nearest OB association to the Sun, Upper Scorpius (145 pc; 5-10 Myr), to constrain the form and shape of the luminosity function and mass spectrum in this…

We report the results of a millimeter interferometric survey of compact 3 mm continuum sources in the inner 5.5'x5.5' region of the Serpens core. We detect 32 discrete sources above 4.0 mJy/beam, 21 of which are new detections at millimeter…