Related papers: A White Dwarf-Main Sequence Binary Unveiled by Tim…

We provide a detailed characterization of 2M07515777+1807352, a post-common envelope eclipsing binary system with a 10.3 d, nearly, but not quite, circular orbit (e = 0.02). This system consists of a massive white dwarf (WD) ($1.08$…

Evidence is presented that 2MASS J03202839-0446358, a late-type dwarf with discrepant optical (M8:) and near-infrared (L1) spectral types, is an as-yet unresolved stellar/brown dwarf binary with late-type M dwarf and T dwarf components.…

The bright subdwarf-O star (sdO), HD 49798, is in a 1.55 day orbit with a compact companion that is spinning at 13.2 seconds. Using the measurements of the effective temperature ($T_{\rm eff}$), surface gravity ($\log g$), and surface…

We have obtained high contrast images of four nearby, faint, and very low mass objects 2MASSJ04351455-1414468, SDSSJ044337.61+000205.1, 2MASSJ06085283-2753583 and 2MASSJ06524851-5741376 (here after 2MASS0435-14, SDSS0443+00, 2MASS0608-27…

The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars with massive compact companions like massive white dwarfs (M>1.0 M$_\odot$), neutron stars, or stellar-mass black…

The NASA Wide-field Infrared Survey Explorer (WISE) has discovered almost all the known members of the new class of Y-type brown dwarfs. Most of these Y dwarfs have been identified as isolated objects in the field. It is known that binaries…

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…

Hot subdwarf (sdB) stars in binary systems with main-sequence (MS) companions provide valuable insights into mass transfer and envelope ejection processes in binary evolution. Their mass ratios, orbital periods, and stellar properties…

We present the discovery of 15 extremely low mass (5 < log{g} < 7) white dwarf candidates, 9 of which are in ultra-compact double-degenerate binaries. Our targeted ELM Survey sample now includes 76 binaries. The sample has a lognormal…

We present the culmination of our near-infrared survey of the optically spectroscopically identified white dwarf stars from the McCook & Sion catalog, conducted using photometric data from the Two Micron All Sky Survey final All Sky Data…

We have spectroscopically confirmed a brown dwarf mass companion to the hydrogen atmosphere white dwarf NLTT5306. The white dwarf's atmospheric parameters were measured using Sloan Digital Sky Survey and X-Shooter spectroscopy as…

The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (muchfuss) aims to discover subdwarf-B stars with massive compact companions such as overmassive white dwarfs (M > 1.0 M_sun), neutron stars or black holes.…

PSR J1738+0333 is one of the four millisecond pulsars known to be orbited by a white dwarf companion bright enough for optical spectroscopy. Of these, it has the shortest orbital period, making it especially interesting for a range 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…

We present the first results of a dedicated search for pulsating white dwarfs (WDs) in detached white dwarf plus main-sequence binaries. Candidate systems were selected from a catalogue of WD+MS binaries, based on the surface gravities and…

We have discovered that the extremely red, low-gravity L7 dwarf 2MASS J11193254-1137466 is a 0.14" (3.6 AU) binary using Keck laser guide star adaptive optics imaging. 2MASS J11193254-1137466 has previously been identified as a likely…

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…

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 report on the detection of the two shortest period non-interacting white dwarf binary systems. These systems, SDSS J143633.29+501026.8 and SDSS J105353.89+520031.0, were identified by searching for radial velocity variations in the…

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…