Related papers: Mid-Infrared High-Contrast Imaging of HD 114174 B …

J191213.72-441045.1 is a binary system composed of a white dwarf and an M-dwarf in a 4.03-hour orbit. It shows emission in radio, optical, and X-ray, all modulated at the white dwarf spin period of 5.3 min, as well as various orbital…

A search of the Two Micron All Sky Survey and Sloan Digital Sky Survey reveals 36 previously unknown high proper motion objects with J<17. Their red-optical colors indicate that 27 are M dwarfs, 8 are early-type L dwarfs, and 1 is a…

We search for stellar and substellar companions of young nearby stars to investigate stellar multiplicity and formation of stellar and substellar companions. We detect common proper-motion companions of stars via multi-epoch imaging. Their…

We present the atmospheric characterization of the substellar companion HD 19467 B as part of the pioneering JWST GTO program to obtain moderate resolution spectra (R$\sim$2,700, 3-5$\mu$m) of a high-contrast companion with the NIRSpec IFU.…

We report the discovery of a companion to the high proper motion star LHS 1589, a nearby high-velocity, low-mass subdwarf. The companion (LHS 1589B) is located 0.224+/-0.004" to the southwest of the primary (LHS 1589A), and is 0.5 magnitude…

Chauvin et al. 2005 imaged a co-moving companion at ~260 AU from the young star AB Pic A. Evolutionary models predictions based on J H K photometry of AB Pic b suggested a mass of ~13 - 14 MJup, placing the object at the deuterium-burning…

We spectroscopically characterize the atmosphere of HD 106906b, a young low-mass companion near the deuterium burning limit. The wide separation from its host star of 7.1" makes it an ideal candidate for high S/N and high-resolution…

We report on multi-band photometric observations of four binary millisecond pulsars with the Gran Telescopio Canarias. The observations led to detection of binary companions to PSRs J1630+3734, J1741+1351 and J2042+0246 in the Sloan g', r'…

Aims: Completing the poorly known substellar census of the solar neighbourhood, especially with respect to the coolest brown dwarfs, will lead to a better understanding of failed star formation processes and binary statistics with different…

We report new spectroscopic results, obtained with UKIRT/CGS4, of a sample of 14 candidate ultracool dwarfs selected from the DENIS (Deep Near-Infrared Survey of the Southern Sky) database. A further object, selected from the 2MASS Second…

We report on photometric and spectroscopic observations of white dwarf companions to four binary radio millisecond pulsars, leading to the discovery of companions to PSRs J0614-3329, J1231-1411 and J2017+0603. We place limits on the…

Located 10.888 pc from Earth, COCONUTS-2b is a planetary-mass companion to a young (150-800 Myr) M3 star, with a wide orbital separation (6471 au) and a low companion-to-host mass ratio ($0.021\pm0.005$). We have studied the atmospheric…

Using astrometric measurements obtained with the FORS2/VLT camera, we are searching for low-mass companions around 20 nearby ultracool dwarfs. With a single-measurement precision of 0.1 milli-arcseconds, our survey is sensitive to a wide…

We present and analyze Subaru/IRCS L' and M' images of the nearby M dwarf VHS J125601.92-125723.9 (VHS 1256), which was recently claimed to have a ~11 M_Jup companion (VHS 1256 b) at ~102 au separation. Our AO images partially resolve the…

We present ZJHKL'M' photometry of a sample of 58 late-M, L, and T dwarfs, most of which are identified from the Sloan Digital Sky Survey and the Two Micron All-Sky Survey. Near-infrared spectra and spectral classifications for most of this…

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…

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…

We present the identification of the COCONUTS-2 system, composed of the M3 dwarf L 34-26 and the T9 dwarf WISEPA J075108.79$-$763449.6. Given their common proper motions and parallaxes, these two field objects constitute a physically bound…

(Abridged) We aim at measuring the near-infrared photometry, and deriving the mass, age, temperature, and surface gravity of WISE J085510.74-071442.5 (J0855-0714), which is the coolest known object beyond the Solar System as of today. We…

We report the discovery of an eclipsing binary -- PTF1 J072456$+$125301-- composed of a subdwarf B (sdB) star ($g'=17.2^m$) with a faint companion. Subdwarf B stars are core helium-burning stars, which can be found on the extreme horizontal…