Related papers: Proper motion Pleiades candidate L-type brown dwar…

We report the discovery of three L dwarfs in the solar vicinity within 30 parsecs. These objects were originally found as proper motion objects from a combination of R and I photographic plates measured as part of the SuperCOSMOS Sky…

[Abridged] In this paper, we present the results of a photometric survey to identify low mass and brown dwarf members of the old open cluster Praesepe (age of 590[+150][-120]Myr and distance of 190[+6.0][-5.8]pc) and use this to infer its…

We have photometrically monitored (Cousins Ic) eight low mass stars and brown dwarfs which are probable members of the Pleiades. We derived rotation periods for two of the stars - HHJ409 and CFHT-PL8 - to be 0.258 d and 0.401 d,…

We present near infrared J-, H- and K-band photometry and optical spectroscopy of low-mass star and brown dwarf (BD) candidates in the Pleiades and Praesepe open clusters. We find that Pleiades stars with K=10.5--13 are rather redder than…

We present the results of spectroscopic follow-up observations for a sample of 71 red objects with high proper motions in the range 0.08-1.14 arcsec/yr as detected using APM and SSS measurements of multi-epoch photographic Schmidt plates.…

We have obtained intermediate resolution spectra of eleven candidate brown dwarf members of the Pleiades open cluster using the Keck II telescope and LRIS spectrograph. Our primary goal was to determine the location of the "lithium…

We have undertaken a differential photometric I band search for variability in three Pleiades brown dwarfs and three very low mass field L dwarfs. Analysis of the resultant time series for the Pleiades brown dwarfs (Teide 1, Calar 3, Roque…

We present a near-infrared (K'-band) survey of 0.7 square degree area in the Alpha Persei open cluster (age = 90 Myr, distance = 182 pc) carried out with the Omega-Prime camera on the Calar Alto 3.5-m telescope. Combining optical data (Rc…

Neuhaeuser & Comeron (1998, 1999) presented direct imaging evidence, as well as first spectra, of several young stellar and sub-stellar M6- to M8-type objects in the Cha I dark cloud. One of these objects is Cha Halpha 2, classified as…

We present the results of a H- and K-band multi-object and long-slit spectroscopic survey of substellar mass candidates in the outer regions of the Orion Nebula Cluster. The spectra were obtained using MOIRCS on the 8.2-m Subaru telescope…

We report the initial results of a VLT/NACO high spatial resolution imaging survey for multiple systems among 58 M-type members of the nearby Upper Scorpius OB association. Nine pairs with separations below 100 have been resolved. Their…

PPl 15 is the first object to have been confirmed as a brown dwarf by the lithium test (in 1995), though its inferred mass was very close to the substellar limit. It is a member of the Pleiades open cluster. Its position in a cluster…

We report new spectroscopic results, obtained with UKIRT/CGS4, of a sample of 14 candidate ultracool dwarfs selected from the DENIS (Deep Near-Infrared Survey of the Southern Sky) database. A further object, selected from the 2MASS Second…

We present an analysis of 23 L dwarfs whose optical spectra display unusual features. Twenty-one were uncovered during our search for nearby, late-type objects using the Two Micron All-Sky Survey while two were identified in the literature.…

The Upper-Scorpius association is the OB association nearest to the Sun (145 pc). Its young age (5 Myr) makes it an ideal place to search for low-mass stars and brown dwarfs, as these objects should be relatively bright. We have performed a…

Benchmark brown dwarfs are those objects for which fiducial constraints are available, including effective temperature, parallax, age, metallicity. We searched for new cool brown dwarfs in 186 sq.deg. of the new area covered by the data…

Intermediate resolution (R=7000) spectroscopy is presented for 76 photometrically selected very low mass (0.04<M<0.3M_{sun}) candidate members of the Sigma Orionis cluster. More than two thirds appear to be genuine cluster members on the…

Using Virtual Observatory tools, we cross-matched the Carlsberg Meridian 14 and the 2MASS Point Source catalogs to select candidate nearby bright M dwarfs distributed over ~ 25,000 deg^2. Here, we present reconnaissance low-resolution…

We present the results of a deep optical 2.6 square degree survey with near infrared follow-up measurements of the intermediate-aged Praesepe open cluster. The survey is complete to I=21.3, Z=20.5, corresponding to ~0.06 Solar Masses…

We report the discovery of twenty-one hitherto unknown bright southern ultracool dwarfs with spectral types in the range M7 to L5.5, together with new observations of a further three late M dwarfs previously confirmed. Three more objects…