Related papers: WISE J061213.85-303612.5: a new T-dwarf binary can…

We analyse archival optical data on the binary companion to the millisecond pulsar \j1045\ obtained with the Very Large Telescope. A possible optical counterpart candidate %source position coincides with the pulsar coordinates is found at…

We present the discovery of 2MASS J21321145+1341584AB as a closely separated (0.066") very low-mass field dwarf binary resolved in the near-infrared by the Keck II Telescope using laser guide star adaptive optics. Physical association is…

I report some observations and calculations related to the new nearby brown dwarf at d = 2 pc discovered by Luhman (2013, ApJ Letters, in press; arXiv:1303.2401). I report archival astrometry and photometry of the new object from IRAS…

WISE J085510.83-071442.5 (hereafter WISE 0855-0714) is the coldest known brown dwarf (~250 K) and the fourth closest known system to the Sun (2.2 pc). It has been previously detected only in the J band and two mid-IR bands. To better…

We present spatially resolved photometric and spectroscopic observations of two wide brown dwarf binaries uncovered by the SIMP near-infrared proper motion survey. The first pair (SIMP J1619275+031350AB) has a separation of 0.691" (15.2 AU)…

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 the discovery with WISE of a significant infrared excess associated with the eclipsing post-common envelope binary SDSSJ 030308.35+005443.7, the first excess discovered around a non-interacting white dwarf+main sequence M dwarf…

WISE has discovered an extraordinary population of hyper-luminous dusty galaxies which are faint in the two bluer passbands ($3.4\, \mu$m and $4.6\, \mu$m) but are bright in the two redder passbands of WISE ($12\, \mu$m and $22\, \mu$m). We…

Circumstellar debris disks are important because of their connection to planetary systems. An efficient way to identify these systems is through their infrared excess. Most studies so far concentrated on early-type or solar-type stars, but…

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…

Using two epochs of 4.5um images from the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope, we recently identified a common proper motion companion to the white dwarf WD 0806-661 that is a candidate for the coldest known…

We present updated results of a high-resolution, magnitude limited (Ks<12 mag) imaging survey of nearby low-mass M6.0-M7.5 field stars. The observations were carried out using adaptive optics at the Gemini North, VLT, Keck II, and Subaru…

We present 6300--10100 {\AA} spectra for a sample of 13 T dwarfs observed using LRIS mounted on the Keck I 10m Telescope. A variety of features are identified and analyzed, including pressure-broadened K I and Na I doublets; narrow Cs I and…

We present near-infrared spectra for a sample of T dwarfs, including eleven new discoveries made using the Two Micron All Sky Survey. These objects are distinguished from warmer (L-type) brown dwarfs by the presence of methane absorption…

The knowledge of the binary properties of metal-poor and solar-metallicity stars can shed light on the potential differences between the formation processes responsible for both types of objects. The aim of the project is to determine the…

Extremely low mass white dwarfs are very rare objects likely formed in compact binary systems. We present MMT optical spectroscopy of 42 low mass white dwarf candidates serendipitously discovered in a survey for hypervelocity B-type stars.…

We present the discovery of seven ultracool brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Near-infrared spectroscopy reveals deep absorption bands of H_2O and CH_4 that indicate all seven of the brown dwarfs…

The white dwarf LHS 3236 (WD1639+153) is shown to be a double-degenerate binary, with each component having a high mass. Astrometry at the U.S. Naval Observatory gives a parallax and distance of 30.86 +/- 0.25 pc and a tangential velocity…

We have compiled L' and M' photometry of 63 single and binary M, L,and T dwarfs obtained at UKIRT using the MKO filter set. This compilation includes new L' data for 8 L dwarfs and 13 T dwarfs and new M' data for 7 L dwarfs, 5 T dwarfs, and…

The severe crowding towards the Galactic plane suggests that the census of nearby stars in that direction may be incomplete. Recently, Scholz reported a new M9 object at an estimated distance d~7 pc (WISE J072003.20-084651.2; hereafter…