Related papers: Evidence for Terrestrial Planetary System Remnants…
The currently feasible method of detection of Earth-mass planets is transit photometry, with detection probability decreasing with a planet's distance from the star. The existence or otherwise of short-period terrestrial planets will tell…
If the photospheres of solar-type stars represent the composition of circumstellar disks from which any planets formed, spectroscopic determinations of stellar elemental abundances offer information on the composition of those planets,…
Dynamically active planetary systems orbit a significant fraction of white dwarf stars. These stars often exhibit surface metals accreted from debris disks, which are detected through infrared excess or transiting structures. However, the…
We report Keck High Resolution Echelle Spectrometer data and model atmosphere analysis of two helium-dominated white dwarfs, PG1225-079 and HS2253+8023, whose heavy pollutions most likely derive from the accretion of terrestrial-type…
Debris discs are commonly detected orbiting main-sequence stars, yet little is known regarding their fate as the star evolves to become a giant. Recent observations of radial velocity detected planets orbiting giant stars highlight this…
White dwarfs are the dense, burnt-out remnants of the vast majority of stars, condemned to cool over billions of years as they steadily radiate away their residual thermal energy. To first order, their atmosphere is expected to be made…
We examine 14 hot white dwarfs for signs of infrared excess using the Spitzer Space Telescope. Twelve of the objects are massive white dwarfs which have been suggested to be the result of binary mergers. The remaining two objects are…
Exoplanetary science has reached a historic moment. The James Webb Space Telescope will be capable of probing the atmospheres of rocky planets, and perhaps even search for biologically produced gases. However this is contingent on…
White dwarfs with metal pollution are caused by the accretion of rocky dust from tidally disrupted minor bodies and are signposts for planetary systems. These minor bodies are perturbed by planets that have survived post-main sequence…
Observations of small extrasolar planets with a wide range of densities imply a variety of planetary compositions and structures. Currently, the only technique to measure the bulk composition of extrasolar planetary systems is the analysis…
Observations of circumstellar disks around stars as a function of stellar properties such as mass, metallicity, multiplicity, and age, provide constraints on theories concerning the formation and evolution of planetary systems. Utilizing…
White dwarfs represent the endpoint of stellar evolution for stars with initial masses between approximately 0.07 msun and 8-10 msun, where msun is the mass of the Sun (more massive stars end their life as either black holes or neutron…
Main sequence stars are commonly surrounded by debris disks, composed of cold dust continuously replenished by a reservoir of undetected dust-producing planetesimals. In a planetary system with a belt of planetesimals (like the Solar…
We develop a semi-analytical model for computing planetary system formation with the aim of explaining the observed diversity of planetary systems architectures and relate this primordial diversity with the initial properties of the disc…
Substellar objects such as brown dwarfs and planets are generally expected to remain detached from their main-sequence host stars unless orbital decay or stellar expansion brings them into contact, leading to rapid engulfment and…
Main sequence stars, like the Sun, are often found to be orbited by circumstellar material that can be categorized into two groups, planets and debris. The latter is made up of asteroids and comets, as well as the dust and gas derived from…
In most extrasolar planetary systems, the present orbits of known giant planets admit the existence of stable terrestrial planets. Those same giant planets, however, have typically eccentric orbits that hint at violent early dynamics less…
White dwarfs and neutron stars are stellar objects with masses comparable to that of our sun. However, as the endpoint stages of stellar evolution, these objects do not sustain any thermonuclear burning and therefore can no longer support…
The occurrence rate of young giant planets from direct imaging surveys is a fundamental tracer of the efficiency with which planets form and migrate at wide orbital distances. These measurements have progressively converged to a value of…
About 25\% -50\% of white dwarfs (WDs) are found to be polluted by heavy elements. It has been argued that the pollution could be caused by the tidal disruption of an approaching planet around the WD, during which a large number of clumps…