Related papers: Stellar Surface Magnetic Fields Impact Limb Darken…
Magnetic fields are hypothesized to inflate the radii of low-mass stars---defined as less massive than 0.8$M_\odot$---in detached eclipsing binaries (DEBs). We investigate this hypothesis using the recently introduced magnetic Dartmouth…
In this study, we investigate the impact of dark matter on the structure and deformation of magnetars. We assume a perturbative approach for the magnetic field deformation and that the dark matter only interacts gravitationally with…
Both stars and planets can lose mass through an expansive wind outflow, often constrained or channeled by magnetic fields that form a surrounding magnetosphere. The very strong winds of massive stars are understood to be driven by…
Recent papers have reported an unexplained cooling of CMB photons passing through galaxies in nearby cosmic filaments $z<0.02$ at the $>5\sigma$ level. Here we show for the first time that this effect is also present at higher redshifts…
An analytical model is developed for the screening of the external magnetic field of a rotating, axisymmetric neutron star due to the accretion of plasma from a disk. The decrease of the field occurs due to the electric current in the…
We calculate simulated images of disks perturbed by embedded small planets. These 10-50 M_Earth bodies represent the growing cores of giant planets. We examine scattered light and thermal emission from these disks over a range of…
The surface rotation rates of young solar-type stars decrease rapidly with age from the end of the pre-main sequence though the early main sequence. This suggests that there is also an important change in the dynamos operating in these…
The distribution of dark matter in dwarf galaxies can have important implications on our understanding of galaxy formation as well as the particle physics properties of dark matter. However, accurately characterizing the dark matter content…
Accreting T Tauri stars are observed to be less luminous in X-rays than non-accretors, an effect that has been detected in various star forming regions. To explain this we have combined, for the first time, a radiative transfer code with an…
We present a method of determining lower limits on the masses of pre-main-sequence (PMS) stars and so constraining the PMS evolutionary tracks. This method uses the red-shifted absorption feature observed in some emission-line profiles of T…
We present the first self-consistent theoretical models of magnetar spectra that take into account the combined effects of the stellar atmosphere and its magnetosphere. We find that the proton cyclotron lines that are already weakened by…
The atmospheric properties of hot exoplanets are expected to be different between the morning and the evening limb due to global atmospheric circulation. Ground-based observations at high spectral resolution have detected this limb…
Asteroseismic methods offer a means to investigate stellar activity and activity cycles as well as to identify those properties of stars which are crucial for the operation of stellar dynamos. With data from CoRoT and \textit{Kepler},…
We introduce an observational tool based on visibility nulls in optical spectro-interferometry fringe data to probe the structure of stellar atmospheres. In a preliminary demonstration, we use both Navy Precision Optical Interferometer…
Ultramagnetized neutron stars or magnetars have been invoked to explain several astrophysical phenomena. We examine how the magnetic field of a magnetar will decay over time and how this decay affects the cooling of the object. We find that…
Binary neutron star mergers provide a laboratory for probing fundamental physics through their gravitational-wave emission and electromagnetic counterparts. In particular, they may allow us to explore signatures of physics beyond the…
The evolution of a star is influenced by its internal rotation dynamics through transport and mixing mechanisms, which are poorly understood. Magnetic fields can play a role in transporting angular momentum and chemical elements, but the…
The simple physics of microlensing provides a well-understood tool with which to probe the atmospheres of distant stars in the Galaxy and Local Group with high magnification and resolution. Recent results in measuring stellar surface…
Quasi-periodic modulations of the stellar light curve may result from dark spots crossing the visible stellar disc. Due to differential rotation, spots at different latitudes generally have different rotation periods. Hence, by studying…
As a planet transits the face of a star, it accelerates along the line-of-sight. The changing delay in the propagation of photons produces an apparent deceleration of the planet across the sky throughout the transit. This persistent…