There are numerous multi-planet systems that have now been detected via a variety of techniques. These systems exhibit a range of both planetary properties and orbital configurations. For those systems without detected planetary transits, a significant unknown factor is the orbital inclination. This produces an uncertainty in the mass of the planets and their related properties, such as atmosph...

We demonstrate the existence of long-lived, large-amplitude eccentric modes in massive, annular particle disks in orbit about a central mass. The lopsided modes we have found precess slowly in the prograde direction at a rate which increases with disk mass and decreases with the amplitude of the distortion. The lopsidedness generally survives for as long as we run the calculations and may last ...

Stars are generally formed in clusters. Prior to the the dispersal of small clusters, which occurs on the time scale of 10 8 yr, dynamical interaction between young stars may also affect the stability and dynamical evolution of their companion planetary systems. Through a series of numerical simulations, we show that distant stellar encounters generally do not strongly modify the compact and ne...

Many planetary nebulae (PNe) exhibit symmetries which range from unremarkable spherical and elliptical shapes, to quite exotic bipolar and point-symmetric shapes. However, there are many which exhibit distinctly non-axisymmetric structure in either (i) the shape of the nebula, or (ii) in the off-centered position of the illuminating star. By examining a large number of well resolved images of P...

Long time coverage and high radial velocity precision have allowed for the discovery of additional objects in known planetary systems. Many of the extrasolar planets detected have highly eccentric orbits, which raises the question of how likely those systems are to host additional planets. We investigate six systems which contain a very eccentric (e > 0.6) planet: HD 3651, HD 37605, HD 45350, H...

We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the host stars’ rotation axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin orbit angles consistent with zero: λ = −...

We consider particles with low free or proper eccentricity that are orbiting near planets on eccentric orbits. Via collisionless particle integration we numerically find the location of the boundary of the chaotic zone in the planet’s corotation region. We find that the distance in semi-major axis between the planet and boundary depends on the planet mass to the 2/7 power and is independent of ...

A compact binary on an eccentric orbit radiates gravitational waves (GWs) at all integer harmonics of its orbital frequency. Thus, the spectral energy distribution, the power and the timescale of GW radiation of a binary on an eccentric orbit are different from those of a binary on a circular orbit. Therefore, in order to predict spectra of gravitational wave background radiation (GWBR) from co...

Abstract Astrometric observations of S-stars provide a unique opportunity to probe the nature Sagittarius-A* (Sgr-A*). In view this, it has become important understand and behavior timelike bound trajectories particles around massive central object. It is known now that whereas Schwarzschild black hole does not allow negative precession for S-stars, naked singularity spacetimes can admit positi...

We compute adiabatic waveforms for extreme mass-ratio inspirals (EMRIs) by ``stitching'' together a long inspiral waveform from sequence of snapshots, each which corresponds to particular geodesic orbit. show that the complicated total can be regarded as sum ``voices.'' Each voice evolves in simple way on timescales, property exploited efficiently produce models faithfully encode properties EMR...