We have obtained ultra-high quality spectra (R=180,000; S/N>300) with unprecedented wavelength coverage (4400 to 7400 Å) for a number of stars covering most of...
Granulation in active regions as compared to quiet regions
A comparative study of the statistical properties of granulation in active and quiet regions is performed. The analysis is based on a high-resolution time...
Granulation in active regions as compared to quiet regions
A comparative study of the statistical properties of granulation in active and quiet regions is performed. The analysis is based on a high-resolution time...
We explore the metallicity dependence of granulation parameters for thousands of red giants observed with Kepler, and find a significant dependence of...
Granule and Supergranule properties derived from solar timeseries
In this paper we mainly aim at the understanding of temporal evolution and spatial characterization of solar granular and supergranular features. For this...
Gravitational Lenses and the Hubble Constant: Present and Future
The best studied gravitational lens is the Twin QSO Q0957+561, and as a result of recent advances in observations and modelling, a ten percent measurement of...
Gravitational microlensing effects on the broad emission lines of quasars .
Multiple images of QSOs are formed when the gravitational field of an intervening galaxy bends the trajectories of the light rays. The granulation of the lens...