Related papers: PHL 5038: A spatially resolved white dwarf + brown…
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…
The discovery of a low luminosity common proper motion companion to the white dwarf GD392 at a wide separation of $46''$ is reported. $BVRI$ photometry suggests a low temperature ($T_{\rm eff}\sim4000$ K) while $JHK$ data strongly indicate…
The white dwarf Giclas 29-38 has attracted much attention due to its large infrared excess and the suggestion that excess might be due to a companion brown dwarf. We observed this object using speckle interferometry at the Keck telescope,…
We report on second-epoch imaging of two candidate planet-hosting white dwarfs stars, WD2105-82 and WD1202-232. Both stars showed evidence of resolved, planet-mass candidate companions in observations using the MIRI mid-infrared imager on…
Using an Extreme Ultraviolet Explorer (EUVE) spectrum, we confirm the identification of a white dwarf companion to the B9.5V star 16 Dra (HD150100), and constrain its surface temperature to lie between 29,000K and 35,000K. This is the third…
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 the unplanned detection of a white dwarf companion to the star HD 218261 in mid-infrared (10-16 $\mu$m) observations with JWST/MIRI. This star was observed as a calibrator for coronagraphic observations of the exoplanet host HR…
We present results from a Hubble Space Telescope imaging search for low-mass binary and planetary companions to 33 nearby brown dwarfs with spectral types of T8-Y1. Our survey provides new photometric information for these faint systems,…
We have discovered a wide separation (188.5") T8 subdwarf companion to the sdM1.5+WD binary Wolf 1130. Companionship of WISE J200520.38+542433.9 is verified through common proper motion over a ~3 year baseline. Wolf 1130 is located 15.83…
T and Y-dwarfs are among the coolest and least luminous objects detected, and they can help to understand the properties of giant planets. Their multiplicity properties can shed light on the formation process. We observed a sample six T…
We report the discovery of a young, 0.16" binary, 2M2234+4041AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field ultracool dwarfs. Spatially resolved near-infrared photometry and spectroscopy…
We searched for binary companions to 20 young brown dwarfs in the Upper Scorpius association (145 pc, 5 Myr, nearest OB association) with the the Laser Guide Star adaptive optics system and the facility infrared camera NIRC2 on the 10 m…
Using the low-resolution mode of the Space Telescope Imaging Spectrograph (STIS) aboard the \emph{Hubble Space Telescope} (HST), we have obtained spatially resolved spectra of 20 ultracool dwarfs. 18 of them belong to 9 known very low-mass…
We present new observations of the faint "Sirius-like" companion discovered to orbit HD 114174. Previous attempts to image HD 114174 B at mid-infrared wavelengths using NIRC2 at Keck have resulted in a non-detection. Our new L'-band…
An important aspect of searching for exoplanets is understanding the binarity of the host stars. It is particularly important because nearly half of the solar-like stars within our own Milky Way are part of binary or multiple systems.…
(abridged) We present the discovery of two T dwarf binaries, 2MASS 1225-2739AB and 2MASS 1534-2952AB, identified in a sample of ten T dwarfs imaged with the Hubble Space Telescope Wide Field Planetary Camera 2. The separations of the two…
We report the discovery of a nearby M5.0V dwarf at 24.6 pc, SCR 1848-6855, that is orbited by an unusual companion causing an astrometric perturbation of more than 200 milli-arcseconds. This is by far the largest perturbation found to date…
Near-infrared photometry and spectroscopy is obtained for a heterogeneous sample of nearby white dwarfs with possible excess flux as identified primarily in the Two Micron All Sky Survey. Among the sample of 43 stars are a number of white…
Identification of white dwarfs (WD) with main-sequence (MS) companions and characterization of their properties can put important constraints on our understanding of binary stellar evolution and guide the theoretical predictions for a wide…
Results from a concerted Hubble Space Telescope (HST) survey of nearby white dwarfs for substellar objects is presented. A total of 7 DAZ white dwarfs with distances of $<$ 50 pc had high contrast and high spatial resolution NICMOS…