相关论文: Eclipse, solar limb darkening function and diamete…
A discussion of the solar diameter and its variations must be linked to the limb darkening function (LDF). We introduce a new method to perform high resolution astrometry of the solar diameter from the ground, through the observations of…
We introduce a new method to perform high resolution astrometry of the solar diameter from the ground, through the observations of eclipses. A discussion of the solar diameter and its variations is linked to the Limb Darkening Function…
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…
The Total Solar Irradiance varies over a solar cycle of 11 years and maybe over cycles with longer period. Is the solar diameter variable over time too? We introduce a new method to perform high resolution astrometry of the solar diameter…
The diameter of the Sun has been measured using Baily's beads during central eclipses, observed with portable telescopes. A blend of tiny emission lines produced in the first several hundred kilometers above the photosphere gives a light…
The solar diameter changes or not? Whatever will be the answer the methods used for its measurements are more and more challenging, and facing new astrophysical and optical problems since the required space resolution is of astrometric…
Stellar limb darkening is the observed variation in brightness of a star between its centre and edge (or limb) when viewed in the plane of the sky. Stellar brightness is maximal at the centre and then decreases radially and monotonically…
We explore the sensitivity of limb darkening coefficients computed from stellar atmosphere models to different least-squares fitting methods. We demonstrate that conventional methods are strongly biased to fitting the stellar limb. Our…
Observations of microlensing transit events can be used to measure the limb darkening of the lensed star. We discuss the advantages and drawbacks of several microlensing light curve inversion methods. The method of choice in this work is…
The measurement of the solar diameter is introduced in the wider framework of solar variability and of the influences of the Sun upon the Earth's climate. Ancient eclipses and planetary transits would permit to extend the knowledge of the…
Context. Limb darkening is an important tool for understanding stellar atmospheres, but most observations measuring limb darkening assume various parameterizations that yield no significant information about the structure of stellar…
Limb-darkening is fundamental in determining transit lightcurve shapes, and is typically modeled by a variety of laws that parametrize the intensity profile of the star that is being transited. Confronted with a transit lightcurve, some…
The non-spherical shape of the Sun has been invoked to explain the anomalous precession of Mercury. A brief history of some methods for measuring solar diameter is presented. Archimedes was the first to give upper and lower values for solar…
We consider the application of interferometry to measuring the sizes and shapes of small bodies in the solar system that cannot be spatially resolved by today's single-dish telescopes. Assuming ellipsoidal shapes, our results indicate that…
The variation of the solar diameter is the subject of hot debates due to the possible effect on Earth climate and also due to different interpretations of long period solar variabilities, including the total solar irradiance. We shortly…
The variation in area of quiet magnetic network measured over the sunspot cycle should modulate the spatially averaged photospheric temperature gradient, since temperature declines with optical depth more gradually in magnetic flux tube…
The ability to observe extrasolar planets transiting their stars has profoundly changed our understanding of these planetary systems. However, these measurements depend on how well we understand the properties of the host star, such as…
This work presents a new method to compute time and wavelength dependent center-to-limb brightness distributions for Classical Cepheids. Our model atmospheres are based on second-order accurate 1-D hydrodynamic calculations, performed in…
The solar limb darkening function is well known and is widely employed in models of the solar atmosphere. However, there has been a lack of systematic spectrally resolved measurements. Therefore we recently decided to start an observing…
We describe a method for determining the limb polarization and limb darkening of stars in eclipsing binary systems, by inverting photometric and polarimetric light curves. Because of the ill-conditioning of the problem, we use the…