Related papers: Kozai Migration Naturally Explains the White Dwarf…
Studies have shown that remnants of destroyed planets and debris-disk planetesimals can survive the volatile evolution of their host stars into white dwarfs, but detection of intact planetary bodies around white dwarfs are few. Simulations…
The merger of close double white dwarfs (CDWDs) is one of the favourite evolutionary channels for producing Type Ia supernovae (SN Ia). Unfortunately, current theories of the evolution and formation of CDWDs are still poorly constrained and…
Although 25%-50% of white dwarfs (WDs) display evidence for remnant planetary systems, their orbital architectures and overall sizes remain unknown. Vibrant close-in (~1 Solar radius) circumstellar activity is detected at WDs spanning many…
The presence of a planetary system can shield a planetesimal disk from the secular gravitational perturbations due to distant outer massive objects (planets or stellar companions). As the host star evolves off the main sequence to become a…
Warm jupiters are an unexpected population of extrasolar planets that are too near to their host to have formed in situ, but distant enough to retain a significant eccentricity in the face of tidal damping. These planets are curiously…
The existence of hot Jupiters has challenged theories of planetary formation since the first extrasolar planets were detected. Giant planets are generally believed to form far from their host stars, where volatile materials like water exist…
We report the discovery of TOI-7019b, the first transiting brown dwarf (BD) known to orbit a star that is part of the Milky Way's ancient thick disk, as defined chemically ([Fe/H] $= -0.79 \pm 0.05$ dex, [$\alpha$/Fe] $= +0.26 \pm 0.05$…
We present TOI-1259Ab, a 1.0 Rjup gas giant planet transiting a 0.71 Rsun K-dwarf on a 3.48 day orbit. The system also contains a bound white dwarf companion TOI-1259B with a projected distance of approximately 1600 AU from the planet host.…
Approximately 25-50% of white dwarfs (WDs) exhibit metal absorption lines in their photospheres, which are attributed to accretion from their remnant planetary systems. Although white dwarfs with detected planetary systems are more likely…
White dwarfs (WDs) represent the final evolutionary stage of most stars, typically originating from progenitor stars with masses below approximately 8 $M_{\odot}$ to 10 $M_{\odot}$. Formation through single-star evolution generally requires…
Gas giants transiting bright nearby stars provide crucial insights into planetary system formation and evolution mechanisms. Most of these planets exhibit certain average characteristics, serving as benchmarks for our understanding of…
Highly eccentric orbits are one of the major surprises of exoplanets relative to the Solar System and indicate rich and tumultuous dynamical histories. One system of particular interest is Kepler-1656, which hosts a sub-Jovian planet with…
The ESA Gaia space mission has revealed a bifurcation of the white dwarf (WD) sequence on the color magnitude diagram in two branches: A and B. While the A branch consists mostly of WDs with H-rich atmospheres, the B branch is not…
White dwarfs have atmospheres that are expected to consist nearly entirely of hydrogen and helium, since heavier elements will sink out of sight on short timescales. However, observations have revealed atmospheric pollution by heavier…
(abridged) We analyze the formation and migration of a proto-Jovian companion in a circumstellar disk in 2d, during the period in which the companion makes its transition from `Type I' to `Type II' migration, using a PPM code. Spiral waves…
We study the steady-state orbital distributions of giant planets migrating through the combination of the Kozai-Lidov (KL) mechanism due to a stellar companion and friction due to tides raised on the planet by the host star. We run a large…
The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD's mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass…
We examine rare evolutionary routes of binary systems where the initially more massive primary star of ~5.5-8.5Mo, forms a white dwarf (WD), while the secondary star of 4Mo < M_2,0 < M_1,0 accretes mass from the evolved primary and later…
Neutron-star (NS) - white-dwarf (WD) mergers may give rise to observable explosive transients, but have been little explored. We use 2D coupled hydrodynamical-thermonuclear FLASH-code simulations to study the evolution of WD debris-disks…
TOI-1899 b is a rare exoplanet, a temperate Warm Jupiter orbiting an M-dwarf, first discovered by Ca\~nas et al. (2020) from a TESS single-transit event. Using new radial velocities (RVs) from the precision RV spectrographs HPF and NEID,…