Related papers: Probing the Stellar Surface of HD 209458 from Mult…
The idea of finding extrasolar planets (ESPs) through observations of drops in stellar brightness due to transiting objects has been around for decades. It has only been in the last ten years, however, that any serious attempts to find ESPs…
The atmosphere of the exoplanet HD 209458b is undergoing sustained mass loss, believed to be caused by X-ray and extreme-ultraviolet (XUV) irradiation from its star. The majority of this flux is not directly observable due to interstellar…
Transmission spectroscopy has provided unprecedented insight into the makeup of exoplanet atmospheres. A transmission spectrum contains contributions from a planet's morning and evening limbs, which can differ in temperature, composition…
Model stellar atmospheres are fundamental tools for understanding stellar observations from interferometry, microlensing, eclipsing binaries and planetary transits. However, the calculations also include assumptions, such as the geometry of…
We present four new transits of the planetary system TrES-3 observed between 2009 May and 2010 June. Among these, the third transit by itself indicates possible evidence for brightness disturbance, which might be the result of the planet…
Aims. The main purpose is to map the radial variation of the stellar space density for the young stellar population in the Galactic anticenter direction in order to understand the structure and location of the Perseus spiral arm. Methods. A…
We investigate observational constraints on the Brans-Dicke cosmological model using observational data coming from distant supernovae type Ia, the Hubble function $H(z)$ measurements, information coming from the Alcock-Paczy{\'n}ski test,…
We present a Python package LDTk that automates the calculation of custom stellar limb darkening (LD) profiles and model-specific limb darkening coefficients (LDC) using the library of PHOENIX-generated specific intensity spectra by Husser…
We present a 3D hydrodynamic study of the effects that different stellar wind conditions and planetary wind structures have on the calculated Ly-$\alpha$ absorptions produced during the transit of HD 209458b. Considering a range of stellar…
We introduce a method to measure with high resolution the solar diameter from the ground, through the eclipse observations by reconsidering the definition of the solar edge. The outer part of the Limb Darkening Function (LDF) is recovered…
HD 209458 b is the first exoplanet on which an atmosphere was detected. Since then, its atmosphere has been investigated using multiple telescopes and instruments. However, many of its atmospheric constraints remain debatable. While HST…
Broadband secondary-eclipse measurements of hot Jupiters have indicated the existence of atmospheric thermal inversions, but their presence is difficult to determine from broadband measurements because of degeneracies between molecular…
While testing a Stromgren spectrophotometer attached to the 1.5-m telescope at the San Pedro Martir observatory, Mexico, a number of A-type stars were observed, one of which, HD 207331, presented clear indications of photometric…
In a line caustic crossing microlensing event, the caustic line moving across the surface of the source star provides a direct method to measure the integrated luminosity profile of the star. Combined with the enormous brightening at the…
In this paper we describe an algorithm and deduce the related mathematical formulae that allows the computation of observed fluxes in stellar and planetary systems with arbitrary number of bodies being part of a transit or occultation…
Very precise measurements of exoplanet transit lightcurves both from ground and space based observatories make it now possible to fit the limb-darkening coefficients in the transit-fitting procedure rather than fix them to theoretical…
The transiting exoplanet HD 149026b is an important case for theories of planet formation and planetary structure, because the planet's relatively small size has been interpreted as evidence for a highly metal-enriched composition. We…
We report high precision spectrophotometric observations of four planetary transits of HD 209458, in the region of the sodium resonance doublet at 589.3 nm. We find that the photometric dimming during transit in a bandpass centered on the…
We present recent observations from the HST-Cosmic Origins Spectrograph aimed at characterizing the auroral emission from the extrasolar planet HD209458b. We obtained medium-resolution (R~18-20,000) far-ultraviolet (1150-1700A) spectra at…
Gravitational microlensing is not only a successful tool for discovering distant exoplanets, but it also enables characterization of the lens and source stars involved in the lensing event. In high magnification events, the lens caustic may…