Related papers: The widest ultracool binary
Stellar-substellar binary systems are quite rare, and provide interesting benchmarks. They constrain the complex physics of substellar atmospheres, because several physical parameters of the substellar secondary can be fixed from the much…
In this paper, we report the discovery of a binary composed of a brown dwarf and a low-mass M dwarf from the observation of the microlensing event OGLE-2014-BLG-0257. Resolution of the very short-lasting caustic crossing combined with the…
Half of the energy emitted by late-T- and Y-type brown dwarfs emerges at 3.5 < lambda um < 5.5. We present new L' (3.43 < lambda um < 4.11) photometry obtained at the Gemini North telescope for nine late-T and Y dwarfs, and synthesize L'…
Aims. We demonstrate the feasibility of determining parallaxes for nearby objects with theWide Field Camera on the United Kingdom Infrared Telescope (UKIRT) using the UKIRT Infrared Deep Sky Survey as a first epoch. We determine physical…
The Latitude Density Search utilized Hyper Suprime-Cam on Subaru Telescope to discover 60 moving objects in the outer Solar System, 54 of which have semi-major axes beyond 30 AU. The images were acquired in exceptional seeing (0.4") and…
We present ten new ultra-cool dwarfs in seven wide binary systems discovered using $\textit{Gaia}$ DR2 data, identified as part of our $\textit{Gaia}$ Ultra-Cool Dwarf Sample project. The seven systems presented here include an L1 companion…
Cool L- and T-type objects were discovered first as companions to stars in 1988 and 1995, respectively. A certain example of the yet cooler Y-type spectral class (Teff <~ 500K?) has not been seen. Recent infrared imaging observations of…
Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass of the brown-dwarf mass function provide critical…
We report the discovery of a very cool, isolated brown dwarf, UGPS 0722-05, with the UKIDSS Galactic Plane Survey. The near-infrared spectrum displays deeper H2O and CH4 troughs than the coolest known T dwarfs and an unidentified absorption…
DENIS J222644.3-750342 is a nearby, very-low-mass, M8.5 V-type star that has been repeatedly targeted by kinematic and activity studies. Thought to be an isolated star, it is actually a wide common-proper-companion at 265 arcsec from the…
We report the discovery of ZTF J2243+5242, an eclipsing double white dwarf binary with an orbital period of just $8.8$ minutes, the second known eclipsing binary with an orbital period less than ten minutes. The system likely consists of…
Theoretical models of low-mass stars continue to be discrepant with observations when used to examine the mass-radius relationship and other physical parameters of individual stars. High-resolution spectroscopy that leads to dynamical…
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…
This is the first of a series of works devoted to investigate cool dwarfs in wide multiple systems. Here, I present Koenigstuhl 4 A and B, two bright, intermediate M dwarfs with a common high proper-motion and separated by 299 arcsec. At…
(abridged) We report the discovery of a very cool brown dwarf, ULAS J003402.77-005206.7 (ULAS J0034-00), identified in UKIDSS DR1. We provide optical, near-infrared, and mid-infrared photometry of the source, and two near-infrared spectra.…
Mass is the fundamental parameter that governs the evolution of stars, brown dwarfs, and gas-giant planets. Thus, direct mass measurements are essential to test the evolutionary and atmospheric models that underpin studies of these objects.…
2MASS J03202839-0446358AB is a recently identified, late-type M dwarf/T dwarf spectroscopic binary system for which both the radial velocity orbit for the primary and spectral types for both components have been determined. By combining…
Low-mass stars in eclipsing binary systems show radii larger and effective temperatures lower than theoretical stellar models predict for isolated stars with the same masses. Eclipsing binaries with low-mass components are hard to find due…
We report the detection of radio emission and orbital motion from the nearby star-brown dwarf binary WISE J072003.20-084651.2AB. Radio observations across the 4.5-6.5 GHz band with the Very Large Array identify at the position of the system…
Using data from the extended Kepler mission in K2 Campaign 10 we identify two eclipsing binaries containing white dwarfs with cool companions that have extremely short orbital periods of only 71.2 min (SDSS J1205-0242, a.k.a. EPIC…