Related papers: Detection of binary companions below the diffracti…
The sodium laser guide star adaptive optics system ALFA, which is installed at the Calar Alto 3.5-m telescope, has been undergoing an intensive optimisation phase. Observations using natural guide stars that are presented in this paper,…
A combination of high-resolution and wide-field imaging reveals two binary stars and one triple star system among the sample of the first 11 stars with planets detected by radial velocity variations. High resolution speckle or adaptive…
We present an empirical analysis of the effectiveness of frame selection (also known as Lucky Imaging) techniques for high resolution imaging. A high-speed image recording system has been used to observe a number of bright stars. The…
In this work, we study the advantages of using a Lucky Imaging camera for the observations of potential planetary microlensing events. Our aim is to reduce the blending effect and enhance exoplanet signals in binary lensing systems composed…
Lucky Imaging combined with a low order adaptive optics system has given the highest resolution images ever taken in the visible or near infrared of faint astronomical objects. This paper describes a new instrument that has already been…
AstraLux is the Lucky Imaging camera for the Calar Alto 2.2-m telescope and the 3.5-m NTT at La Silla. It allows nearly diffraction limited imaging in the SDSS i' and z' bands of objects as faint as i'=15.5mag with minimum technical effort.…
Through selection of short exposure images we achieve diffraction-limited I-band imaging from well-figured ground-based telescopes as large as 2.5 m diameter. The faint limiting magnitude and large isoplanatic patch size for the Lucky…
High contrast imaging at optical wavelengths is limited by the modest correction of conventional near-IR optimized AO systems.We take advantage of new fast and low-readout-noise detectors to explore the potential of fast imaging coupled to…
It is widely believed that adaptive optics only has a role in correcting turbulent wavefronts on large telescopes using very bright reference stars. Unfortunately these are very scarce and many astronomical targets require wavefront…
We survey a sample of 32 M5-M8 stars with distance < 40pc for companions with separations between 0.1 arcsec and 1.5 arcsec and with Delta m_i <5. We find five new VLM binaries with separations between 0.15 arcsec and 1.1 arcsec, including…
Modern image restoration and super-resolution methods utilize deep learning due to its superior performance compared to traditional algorithms. However, deep learning typically requires large labeled training datasets, which are rarely…
The potential of combining Adaptive Optics (AO) and Lucky Imaging (LI) to achieve high precision astrometry and differential photometry in the optical is investigated by conducting observations of the close 0\farcs1 brown dwarf binary…
We present measurements in the context of a survey of southern hemisphere binary and multiple stellar systems observed with the Zorro Speckle dual diffraction-limited optical imaging camera on the 8.1m Gemini-South telescope carried out…
Presented here is list of 50 pairs quasi-evenly spaced over the northern sky, and that have Separations and Position Angles accurate at the milli-arcsec, and milli-degree level. These pairs are suggested as calibration pairs for lucky…
We present the results of 938 speckle measures of double stars and suspected double stars drawn mainly from the Hipparcos Catalogue, as well as 208 observations where no companion was noted. One hundred fourteen pairs have been resolved for…
A sample of 14 pre-main sequence visual binary systems in southern star-forming regions were imaged at 2 um with the Keck I telescope to search for tertiary companions, scattered-light disks, and compact nebulae at linear scales of 5-100…
(abridged) Context. Wide binaries are a potential pathway for the formation of hot Jupiters. The binary fraction among host stars is an important discriminator between competing formation theories, but has not been well characterised.…
The new technique of Speckle Stabilization has great potential to provide optical imaging data at the highest angular resolutions from the ground. While Speckle Stabilization was initially conceived for integral field spectroscopic…
We characterize the sensitivity of a double point-spread function (PSF) fitting algorithm -- employing empirical, position-dependent PSF models -- for detecting companions using the infrared channel of the Wide Field Camera 3 (WFC3/IR) on…
We present the results of an all-sky survey made with the Fine Guidance Sensor on Hubble Space Telescope to search for angularly resolved binary systems among the massive stars. The sample of 224 stars is comprised mainly of Galactic O- and…