Related papers: Characterization of the Benchmark Binary NLTT 3337…
We report on the discovery of the extremely low-mass, hydrogen-rich white dwarf, NLTT 11748. Based on measurements of the effective temperature (8540+/-50 K) and surface gravity (log g = 6.20+/-0.15) obtained by fitting the observed Balmer…
Late M-type dwarfs in the solar neighborhood include a mixture of very low-mass stars and brown dwarfs which is difficult to disentangle due to the lack of constraints on their age such as trigonometric parallax, lithium detection and space…
We present Keck LGS AO imaging and aperture masking observations of the M8+L7 binary LHS 2397aAB. Together with archival HST, Gemini-North, and VLT data, our observations span 11.8 years of the binary's 14.2-year orbital period. We…
We aim to revisit the system AB Pic which has a known companion at the exoplanet/ brown-dwarf boundary. We based this study on a rich set of observations to investigate the companion's orbit and atmosphere. We composed a spectrum of AB Pic…
(Abridged) We aim to determine the trigonometric parallaxes and proper motions of a sample of ten field L0-L5 dwarfs with spectroscopic evidence for low-gravity atmospheres. We obtained J and Ks imaging data using 2-4-m class telescopes…
We combine new high resolution imaging and spectroscopy from Keck/NIRC2, Discovery Channel Telescope/DSSI, and Keck/HIRES with published astrometry and radial velocities to measure individual masses and orbital elements of the GJ 3305 AB…
We have obtained multi-fibre intermediate-resolution optical spectroscopy of 94 photometric and proper motion selected low-mass star and brown dwarf candidates in Upper Sco with AAT/AAOmega. We have estimated the spectral types and measured…
This paper presents a photometric and spectroscopic study of the short-period binary star Cl*~Melotte~111~AV~1224. Measurements in the $B$, $V$, and $R$ passbands obtained during three observing runs between 2014 and 2017 and…
We present Lick Natural Guide Star Adaptive Optics observations of the L8 brown dwarf Gliese 337C, which is resolved for the first time into two closely separated (0"53+/-0"03), nearly equal magnitude components with a K_s flux ratio of…
Binarity and multiplicity appear to be a common outcome in star formation. In particular, the binary fraction of massive (OB-type) stars can be very high. In many cases, the further stellar evolution of these stars is affected by binary…
We present spectroscopic analysis of the low mass binary star system GJ 660.1AB, a pair of nearby M dwarfs for which we have obtained separated near-infrared spectra (0.9-2.5 $\mu$m) with the SpeX spectrograph. The spectrum of GJ 660.1B is…
Luhman (2013) has reported the discovery of a brown dwarf binary system only 2.01+/-0.15 pc from the Sun. The binary is well-resolved with a projected separation of 1.5", and spectroscopic observations have identified the components as…
Massive binary systems are important laboratories in which to probe the properties of massive stars and stellar physics in general. In this context, we analysed optical spectroscopy and photometry of the eccentric short-period early-type…
We report two binary systems, LAMOST J035540+381550 (hereafter J035540) and LAMOST J035916+400732 (hereafter J035916), identified through the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low-resolution survey (LRS).…
We present first results from follow-up of targets in the northern hemisphere Beta Pictoris and AB Doradus moving group candidate list of Schlieder, Lepine, and Simon (2012). We obtained high-resolution, near-infrared spectra of 27…
We have carried out high angular resolution near-infrared imaging and low-resolution (R~1000) spectroscopy of the nearest known brown dwarf, Eps Indi B, using the ESO VLT NAOS/CONICA adaptive optics system. We find it to be a close binary…
As part of a comprehensive effort to characterize the nearest stars, the CHIRON echelle spectrograph on the CTIO/SMARTS 1.5m telescope is being used to acquire high resolution (R = 80000) spectra of K dwarfs within 50 parsecs. This paper…
Even though it was discovered more than a decade ago, LSR1610-0040 remains an enigma. This object has a peculiar spectrum that exhibits some features typically found in L subdwarfs, and others common in the spectra of more massive M dwarf…
As deep spectroscopic campaigns extend to higher redshifts and lower stellar masses, the interpretation of galaxy spectra depends increasingly upon models for very young stellar populations. Here we present new HST/COS ultraviolet…
We have imaged $\epsilon$ Indi B, the closest brown dwarf binary known, with VISIR at the VLT in three narrow-band mid-infrared bandpasses located around 8.6$\mu$m, 10.5$\mu$m and 11.3$\mu$m. We are able to spatially resolve both…