Related papers: Detection of binary companions below the diffracti…
Context. A key property of massive stars is their high degree of multiplicity, which can impact their evolution and end-of-life products. The Southern Massive Stars at High Angular Resolution survey (smash+) use interferometric and…
(Abridged) Lunar occultations (LO) are a very efficient and powerful technique, that achieves the best combination of high angular resolution and sensitivity possible today at near-infrared wavelengths. Given that the events are fixed in…
To image faint substellar companions obscured by the stellar halo and speckles, scattered light from the bright primary star must be removed in hardware or software. We apply the "locally-optimized combination of images" (LOCI) algorithm to…
Since its launch in 2013, the Gaia space telescope has provided precise measurements of the positions and magnitudes of over 1 billion stars. This has enabled extensive searches for stellar and sub-stellar companions through astrometric and…
Although many exoplanets have been indirectly detected over the last years, direct imaging of them with ground-based telescopes remains challenging. In the presence of atmospheric fluctuations, it is ambitious to resolve the high brightness…
The vast majority of extrasolar planets are detected by indirect detection methods such as transit monitoring and radial velocity measurements. While these methods are very successful in detecting short-periodic planets, they are mostly…
For conventional imaging, the imaging resolution limit is given by the Rayleigh criterion. Exploiting the prior knowledge of imaging object's sparsity and fixed optical system, imaging beyond the conventional Rayleigh limit, which is backed…
In addition to constructing a Galactic matter mass function free from the bias induced by the hydrogen-burning limit, gravitational microlensing allows one to construct a mass function which is less affected by the problem of unresolved…
We present a concept of the X-ray imaging system with high angular-resolution and moderate sensitivity. In this concept, a two-dimensional detector, i.e., imager, is put at a slightly out-of-focused position of the focusing mirror, rather…
The presence of stellar companions around planet hosting stars influences the architecture of their planetary systems. To find and characterise these companions and determine their orbits is thus an important consideration to understand…
We explore the possibility of detecting very faint, very close-in stellar companions using large aperture ground-based telescopes and the technique of optical speckle imaging. We examine the state of high angular resolution speckle imaging…
We conducted a deep survey of resolved sub-systems among wide binaries with solar-type components within 67 pc from the Sun. Images of 61 stars in the K and H bands were obtained with the NICI adaptive-optics instrument on the 8-m…
In this paper we present the Adaptive Optics Lucky Imager (AOLI), a state-of-the-art instrument which makes use of two well proved techniques for extremely high spatial resolution with ground-based telescopes: Lucky Imaging (LI) and…
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…
Since 2007, close binary and multiple stars are observed by speckle interferometry at the 4.1 m Southern Astrophysical Research (SOAR) telescope. The HRCam instrument, observing strategy and planning, data processing and calibration…
Sparse aperture masking interferometry (SAM) is a high resolution observing technique that allows for imaging at and beyond a telescope's diffraction limit. The technique is ideal for searching for stellar companions at small separations…
The Adaptive Optics Lucky Imager (AOLI) is a new instrument under development to demonstrate near diffraction limited imaging in the visible on large ground-based telescopes. We present the adaptive optics system being designed for the…
We report on 25 sub-arcsecond binaries, detected for the first time by means of lunar occultations in the near-infrared as part of a long-term program using the ISAAC instrument at the ESO Very Large Telescope. The primaries have magnitudes…
We report on 13 sub-arcsecond binaries, detected by means of lunar occultations in the near-infrared at the ESO Very Large Telescope. They are all first-time detections, except for the visual binary HD~158122 which we resolved for the first…
In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and…