Related papers: Probing the Upper Scorpius mass function in the pl…

We present results from a large spectroscopic survey of the nearest young association to the Sun, Upper Scorpius, conducted using 2dF/HERMES on the Anglo-Australian Telescope. We use spectroscopic youth criteria such as Li-equivalent widths…

We present the results of a search for wide binary systems among 783 members of three nearby young associations: Taurus-Auriga, Chamaeleon I, and two subgroups of Upper Scorpius. Near-infrared (JHK) imagery from 2MASS was analyzed to search…

Infrared spectroscopy provides a powerful diagnostic for probing the mineralogical properties of dust grains in the terrestrial planet-forming regions of protoplanetary disks. The Upper Scorpius association offers an excellent laboratory…

We report on a search for low mass companions within 10 AU of the star Fomalhaut, using narrow band observations at 4.05 microns obtained with the Apodizing Phase Plate (APP) coronagraph on the VLT/NaCo. Our observations place a model…

We present ALMA observations of 106 G-, K-, and M-type stars in the Upper Scorpius OB Association hosting circumstellar disks. With these data, we measure the 0.88 mm continuum and $^{12}$CO $J$ = 3$-$2 line fluxes of disks around low-mass…

We have used infrared images obtained with the Wide Field Camera 3 on board the Hubble Space Telescope to search for planetary-mass brown dwarfs in the star-forming cluster IC 348. In those images, we have identified 12 objects that have…

Thanks to its exceptional near-infrared photometry, JWST can effectively contribute to the discovery, characterization, and understanding of multiple stellar populations in globular clusters, especially at low masses where the Hubble Space…

I have used mid-infrared (IR) photometry from the Wide-field Infrared Survey Explorer (WISE) to perform a census of circumstellar disks among ~10,000 candidate members of the Sco-Cen complex that were recently identified with data from the…

Massive stars are recognized for their high degree of multiplicity, yet the mass ratio regime below 0.1 remains insufficiently explored. It is therefore unknown whether extremely low-mass (possibly substellar) companions can form and…

Studies of the mass function (MF) of open clusters of different ages allow us to probe the efficiency with which brown dwarfs evaporate from clusters to populate the field. Surveys of older clusters (age >100 Myr) are not affected so…

We present population synthesis models of viscous protoplanetary disks subject to mild external far-ultraviolet (FUV) radiation fields ($F_{\rm UV}=1\text{-}100\,$G$_0$). Our simulations focus on gas disk evolution, exploring stellar masses…

We consider the mass distribution of the nine unseen companions orbiting solar-type stars with minimum possible masses in the planetary mass range reported as of March 1998. We compare the mass distribution of these nine extrasolar planet…

The nearby young sigma Orionis cluster (~360 pc, ~3 Ma) is becoming one of the most important regions for the study of ultra low-mass star formation and its extension down to the mass regimes of the brown dwarfs and planetary-mass objects.…

We present an RI photometric survey covering an area of 430 arcmin^2 around the multiple star Sigma Orionis. The observations were conducted with the 0.8 m IAC-80 Telescope at the Teide Observatory. The survey limiting R and I magnitudes…

The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions…

Adaptive optics corrected images obtained with the CIAO instrument at the Subaru 8.2-meter telescope show the presence of two subarsecond companions to the nearby (d=19.3 pc) young star GJ 900, which was previously classified as a single…

A comprehensive census of the stellar content of the nearby OB associations is presented, based on Hipparcos positions, proper motions, and parallaxes. Moving groups are identified by combining de Bruijne's refurbished convergent point…

We performed a deep wide field optical survey of the young (~100-150 Myr) open cluster Blanco1 to study its low mass population well down into the brown dwarf regime and estimate its mass function over the whole cluster mass range.The…

To address the statistics of binary stars in the 8-Myr old Upper Scorpius star formation region, we conducted speckle-interferometric survey of 614 association members more massive than 0.4 Msun (spectral types earlier than M3V) based on…

We present 237 new spectroscopically confirmed pre-main-sequence K and M-type stars in the young Upper Scorpius subgroup of the Sco-Cen association, the near- est region of recent massive star formation. Using the Wide-Field Spectrograph at…