Related papers: Keck Imaging of Binary L Dwarfs

We report resolved near-infrared spectroscopy and photometry of the recently identified brown dwarf binary WISE J104915.57-531906.1AB, located 2.02+/-0.15 pc from the Sun. Low-resolution spectral data from Magellan/FIRE and IRTF/SpeX reveal…

We present low-resolution spectroscopy of newly-discovered candidate companions to three stars in the Solar Neighbourhood. All three companions are M dwarfs, with spectral types ranging from M4 to M9.5. In two cases, G85-55`B' (M6) and…

We present Keck II laser guide star adaptive optics observations of the brown dwarf WISEP J061135.13-041024.0 showing it is a binary with a component separation of 0.4". This system is one of the six known resolved binaries in which the…

The ROSAT WFC survey has provided us with evidence for the existence of a previously unidentified sample of hot white dwarfs (WD) in non-interacting binary systems, through the detection of EUV and soft X-ray emission. These stars are…

Multiple radial velocity observations have been obtained for a large sample of local field subdwarf B (sdB) stars over a period of two years. SdB stars appear to fall into three distinct groups based on their kinematic and spectroscopic…

I present observations of a new faint double, 2MASS J11011926-7732383AB, toward the Chamaeleon I star-forming region. From optical and near-infrared images of the pair, I measure a separation of 1.44" and extract RIJHK_s photometry of the…

We present observations of a new very low mass field binary, discovered during an infrared imaging survey of 250 DENIS L and very late-M dwarfs. DENIS-J055146.0-443412.2 is an M8.5+L0 pair, with a physical separation of over 200 AU. This…

We present the second set of discoveries from Keck Observations in the INfrared of Taurus and $\rho$ Oph Exoplanets And Ultracool dwarfs (KOINTREAU), an adaptive optics survey of young stars in the Taurus and $\rho$ Oph star-forming regions…

(Abridged). We report on the linear polarimetric observations in the Johnson I filter of 44 M6-L7.5 ultracool dwarfs (2800-1400 K). Eleven (10 L and 1 M) dwarfs appear to have significant linear polarization (P = 0.2-2.5%). We have compared…

In a search for common proper motion companions using the VISTA Hemisphere Survey and 2MASS catalogs we have identified a very red (J-Ks=2.47 mag) late-L dwarf companion of a previously unrecognized M dwarf VHS J125601.92-125723.9, located…

A near-infrared excess is detected at the white dwarf PHL5038 in UKIDSS photometry, consistent with the presence of a cool, substellar companion. We have obtained H- and K-grism spectra and images of PHL5038 using NIRI on Gemini North. The…

We present the discovery of a companion to the Y-dwarf, CWISEP J193518.59-154620.3, the second Y-Y dwarf binary detected to date. Y-dwarfs are the coldest known free-floating objects ($<$ 500 K) and on average represent the lowest mass…

We describe radial velocity observations of a large sample of apparently single white dwarfs (WDs), obtained in a long-term effort to discover close, double-degenerate (DD) pairs which might comprise viable Type Ia Supernova (SN Ia)…

We present the results of a deep-imaging search for wide companions to low-mass stars and brown dwarfs using NSFCam on IRTF. We searched a sample of 132 M7-L8 dwarfs to magnitude limits of $J \sim 20.5$ and $K \sim 18.5$, corresponding to…

We present the completion of a program to cross-correlate the SDSS Data Release 1 and 2MASS Point Source Catalog in search for extremely red L and T dwarfs. The program was initiated by Metchev and collaborators, who presented the findings…

Near-infrared spectra from the IRTF/SpeX and Blanco/ARCoIRIS telescope/instrument combinations are used for spectroscopic classification, to measure radial velocities and for the inference of astrophysical properties of 51 Gaia-selected…

Excess infrared flux from white dwarf stars is likely to arise from a dusty debris disk or a cool companion. In this work, we present near-infrared spectroscopic observations with Keck/MOSFIRE, Gemini/GNIRS, and Gemini/Flamingos-2 of seven…

We report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV 1256-62AB, a…

We report near-infrared spectral model fits to seven distant L- and T-type dwarfs observed with the JWST Near Infrared Spectrograph (NIRSpec) as part of the Red Unknowns: Bright Infrared Extragalactic Survey (RUBIES). Comparison of 0.9-2.5…

Quanz and coworkers have reported the discovery of the coolest known member of the Taurus star-forming complex (L2+/-0.5) and Barrado and coworkers have identified a possible protostellar binary brown dwarf in the same region. We have…