Related papers: A white dwarf bound to the transiting planetary sy…

We use 156 044 white dwarf candidates with $\geq5\sigma$ significant parallax measurements from the Gaia mission to measure the velocity dispersion of the Galactic disc; $(\sigma_U,\sigma_V,\sigma_W) = (30.8, 23.9, 20.0)$ km s$^{-1}$. We…

We report the detection of V1298 Tau b, a warm Jupiter-sized planet ($R_P$ = 0.91 $\pm$ 0.05~ $R_\mathrm{Jup}$, $P = 24.1$ days) transiting a young solar analog with an estimated age of 23 million years. The star and its planet belong to…

White dwarfs are the end state of most stars, including the Sun, after they exhaust their nuclear fuel. Between 1/4 and 1/2 of white dwarfs have elements heavier than helium in their atmospheres, even though these elements should rapidly…

Studies of cool white dwarfs in the solar neighbourhood have placed a limit on the age of the Galactic disk of 8-9 billion years. However, determining their cooling ages requires the knowledge of their effective temperatures, masses, radii,…

We have performed extensive simulations to explore the possibility of detecting eclipses and transits of close, sub-stellar and planetary companions to white dwarfs in WASP light-curves. Our simulations cover companions $\sim0.3\Re<{\rm…

We use Gaia DR2 kinematic data and white dwarf evolutionary models to determine that the young and ultramassive white dwarf GD 50 is a likely member of the AB Doradus moving group. Comparison with the Montr\'eal white dwarf evolutionary…

We present preliminary limits on the presence of planets around white dwarf stars using the IRAC photometer on the Spitzer space telescope. Planets emit strongly in the mid-infrared which allows their presence to be detected as an excess at…

WASP-80b is a missing link in the study of exo-atmospheres. It falls between the warm Neptunes and the hot Jupiters and is amenable for characterisation, thanks to its host star's properties. We observed the planet through transit and…

We report the discovery, from WASP and CORALIE, of a transiting exoplanet in a 1.54-d orbit. The host star, WASP-36, is a magnitude V = 12.7, metal-poor G2 dwarf (Teff = 5959 \pm 134 K), with [Fe/H] = -0.26 \pm 0.10. We determine the planet…

We have performed a comprehensive ground-based observational program aimed at characterizing the circumstellar material orbiting three single white dwarf stars previously known to possess gaseous disks. Near-infrared imaging unambiguously…

We report the discovery of a new transiting planet in the Southern Hemisphere. It has been found by the WASP-south transit survey and confirmed photometrically and spectroscopically by the 1.2m Swiss Euler telescope, LCOGT 2m Faulkes South…

White dwarfs (WDs) offer unrealized potential in solving two problems in astrophysics: stellar age accuracy and precision. WD cooling ages can be inferred from surface temperatures and radii, which can be constrained with precision by high…

In a previous study, we analysed the spectra of 230 cool ($T_\mathrm{eff}$ < 9000 K) white dwarfs exhibiting strong metal contamination, measuring abundances for Ca, Mg, Fe and in some cases Na, Cr, Ti, or Ni. Here we interpret these…

WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves of one transit event, obtained simultaneously using two defocussed telescopes. These data were taken…

Observational tests of stellar and Galactic chemical evolution call for the joint knowledge of a star's physical parameters, detailed element abundances, and precise age. For cool main-sequence (MS) stars the abundances of many elements can…

WASP-148 is a recently announced extra-solar system harbouring at least two giant planets. The inner planet transits its host star. The planets travel on eccentric orbits and are near the 4:1 mean-motion resonance, which implies significant…

Using observations of Spitzer/IRAC, we report the serendipitous discovery of excess infrared emission from a single white dwarf PG 0010+280. At a temperature of 27,220 K and a cooling age of 16 Myr, it is the hottest and youngest white…

We present the discovery of the widest known ultracool dwarf - white dwarf binary. This binary is the first spectroscopically confirmed widely separated system from our target sample. We have used the 2MASS and SuperCOSMOS archives in the…

WASP-128 is a relatively bright (V= 12.37) G0-dwarf, known to host a transiting brown dwarf in a short-period orbit (Hod\v{z}i\'c et al. 2018 arXiv:1807.07557 (H18)). Very few such objects are known, which makes WASP-128 a prime target for…

Hot Jupiters have been perceived as loners devoid of planetary companions in close orbital proximity. However, recent discoveries based on space-borne precise photometry have revealed that at least some fraction of giant planets coexists…