Related papers: Imaging binary stars by the cross-correlation tech…
We describe a multispeckle dynamic light scattering technique capable of resolving the motion of scattering sites in cases that this motion changes systematically with time. The method is based on the visibility of the speckle pattern…
We present a robust and fast algorithm for performing astrometry and source cross-identification on two dimensional point lists, such as between a catalogue and an astronomical image, or between two images. The method is based on minimal…
The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. We…
While a large fraction of the stars are in multiple systems, our understanding of the processes leading to the formation of these systems is still inadequate. Given the large theoretical uncertainties, observation plays a basic role. Here…
We study the inverse problem of localization (imaging) of a laser beam from measurements of the intensity of light scattered off-axis by a Poisson cloud of small particles. Starting from the wave equation, we analyze the microscopic…
The Transiting Exoplanet Survey Satellite (TESS) is conducting a two-year wide-field survey searching for transiting exoplanets around nearby bright stars that will be ideal for follow-up characterization. To facilitate studies of planet…
A new technique based on superposition of two speckle patterns is proposed and demonstrated for controlled modulation of the spatial polarization distribution of the resultant speckle. It is demonstrated both theoretically and…
We present a model for the formation of high-mass close binary systems in the context of forming massive stars through gas accretion in the centres of stellar clusters. A low-mass wide binary evolves under mass accretion towards a high-mass…
Significant fraction of barred galaxies hosts secondary bar-like structures on optical and NIR images. The circumnuclear dynamics of double-barred objects are still not well understood, observational data concerning kinematics are…
Context. Double eclipsing binaries are gravitationally bound quadruple systems in a 2+2 configuration where both of the binaries are eclipsing. These systems are interesting objects to better understand stellar formation, to investigate the…
Speckle patterns observed in coherent optical imaging reflect important characteristic information of the scattering object. To capture speckle patterns, angular resolved or oblique illumination geometries are usually employed in…
Spatially entangled photon pairs (biphotons) generated by spontaneous parametric down-conversion offer unique opportunities for quantum imaging, but image-plane biphoton correlations are difficult to observe with camera-based detectors.…
Direct detection is a very promising field in exoplanet science. It allows the detection of companions with large separation and allows their spectral analysis. A few planets have already been detected and are under spectral analysis. But…
We present scientific results obtained with a recently commissioned \'{e}chelle spectrograph on the 0.5-m Solaris-1 telescope in the South African Astronomical Observatory. BACHES is a low-cost slit \'{e}chelle spectrograph that has a…
We present a powerful new algorithm that combines both spatial information (event locations and the point spread function) and spectral information (photon energies) to separate photons from overlapping sources. We use Bayesian statistical…
We present the new speckle camera PISCO2 made in 2010-2012, for the 76-cm refractor of C\^ote d'Azur Observatory. It is a focal instrument dedicated to the observation of visual binary stars using high angular resolution speckle…
The majority of massive classical Be stars are thought to be binary interactions products. Their rapid rotation and often strong, variable, and emission-line dominated spectrum, make spectroscopic analysis challenging. Hence, robust binary…
The new photometric space-borne survey missions CoRoT and Kepler will be able to detect minute flux variations in binary stars due to relativistic beaming caused by the line-of-sight motion of their components. In all but very short period…
We propose and demonstrate an interferometric scheme for measuring the two-dimensional two-point cross-spectral density function in a two-shot manner. Our scheme comprises a Michelson interferometer with a converging lens in one of the arms…
The dark-speckle method (Labeyrie 1995) combines features of speckle interferometry and adaptive optics to provide images of faint circumstellar material. We present preliminary results of observations, and simulations concluding to the…