We report high-precision, high-cadence photometric measurements of the star HD 209458, which is known from radial velocity measurements to have a planetary-mass companion in a close orbit. We detect two separate transit events at times that are consistent with the radial velocity measurements. In both cases, the detailed shape of the transit curve due to both the limb darkening of the star and ...

This document discusses a numerical analysis method for low thrust trajectory propagation known as the proximity quotient or Q-Law. The process uses a Lyapunov feedback control law developed by Petropoulos [1] to propagate trajectories of spacecraft by minimizing the user defined function at the target orbit. A simplified propagator is created from the core mechanics of this method in MATLAB an...

A general method of deprojecting two-dimensional images to reconstruct the three dimensional structure of the projected object – specifically X-ray, Sunyaev-Zel'dovich (SZ) and gravitational lensing maps of rich clusters of galaxies – assuming axial symmetry (Zaroubi et al. 1998), is considered. Here we test the applicability of the method for realistic, numerically simulated galaxy clusters, v...

We study the effects of dust in hydrodynamic simulations of spiral galaxies when different radial metallicity gradients are assumed. SUNRISE, a Monte-Carlo radiative-transfer code, is used to make detailed calculations of the internal extinction of disk galaxies caused by their dust content. SUNRISE is used on eight different Smooth Particle Hydrodynamics (SPH) simulations of isolated spiral ga...

Aims. We address the problem where the X-ray emission lines are formed and investigate orbital dynamics using Chandra HETG observations, photoionizing calculations and numerical wind-particle simulations. The aims were to set constraints on the masses of the components of this close binary system consisting of a Wolf-Rayet (WR) star and a compact component and to investigate the nature of the l...

We present high resolution time-resolved optical spectra of the high inclination short orbital period dwarf nova V893 Sco. We performed spectral analysis through radial velocity measurements, Doppler mapping, and ratioed Doppler maps. Our results indicate that V893 Sco's accretion disk is dissimilar to WZ Sge's accretion disk, and does not fit any of the current accretion disk models. We derive...

We have obtained medium resolution spectra of the neutron star X-ray transient Aql X–1 during quiescence. We determine the spectral type of the companion star to be K1 and also estimate its rotation speed to be 62 +30 −20 km s −1. By measuring the width of the Hα emission line profile of the accretion disc, we estimate the binary inclination to ∼ 50 • and also estimate the semi-amplitude of the...

Surgical correction for ulnocarpal abutment syndrome after malunited distal radius fracture remains controversial. We reviewed sixteen patients (7 men, 9 women) who underwent isolated ulnar-shortening osteotomy for ulnar wrist pain as their main complaint. Mean age was 48 years. The range of flexion-extension increased from 81 degrees to 103 degrees, and range of supination-pronation from 120 d...

We have obtained I-band photometry of the neutron star X-ray transient Aql X–1 during quiescence. We find a periodicity at 2.487 c d −1 , which we interpret as twice the orbital frequency (19.30±0.05 h). Folding the data on the orbital period, we model the light curve variations as the ellipsoidal modulation of the secondary star. We determine the binary inclination to be 20 • –31 • (90 per cen...

We present optical and X-ray data of the Cataclysmic Variable RX0744{52 discovered using ROSAT by Motch et al. High resolution spectroscopy centred on the H line indicates a probable orbital period of 3.60 hrs. From its distance (obtained using polarimetry), its X-ray luminosity, its X-ray colour and its X-ray/UV+Opt ratio, we suggest that RX0744{52 is an new Intermediate Polar. The absence of ...