Related papers: Star-Cluster Astrometry with Ground-Based Wide Fie…

Space astrometry is capable of sub-microarcsecond measurements of star positions. A hundred visits over several years could yield relative astrometric precision of ~0.1 uas, below the astrometric signature (0.3 uas) of a Sun-Earth system at…

The advent of next-generation imaging telescopes such as LSST and Pan-STARRS has revitalized the need for deep and precise reference frames. The proposed weak-lensing observations with these facilities put the highest demands on image…

New micro-satellite constellations enable unprecedented systematic monitoring applications thanks to their wide coverage and short revisit capabilities. However, the large volumes of images that they produce have uneven qualities, creating…

The idea of using stellar photometry for atmospheric monitoring for optical experiments in high-energy astrophysics is seemingly straightforward, but reaching high precision of the order of 0.01 in the determination of the vertical aerosol…

The accurate measurement of stellar masses over a wide range of galaxy properties is essential for better constraining models of galaxy evolution. Emission line galaxies (ELGs) tend to have better redshift estimates than continuum-selected…

Obtaining accurate photometry of bright stars from the ground remains tricky because of the danger of overexposure of the target and/or lack of suitable nearby comparison star. The century-old method of the objective wire mesh used to…

In this article we identify and discuss various statistical and systematic effects influencing the astrometric accuracy achievable with MICADO, the near-infrared imaging camera proposed for the 42-metre European Extremely Large Telescope…

High precision astrometry aims at source position determination to a very small fraction of the diffraction image size, in high SNR regime. One of the key limitations to such goal is the optical response variation of the telescope over a…

The 22 GHz H_2O masers in the circumstellar envelope of the Mira variable star U Her have been observed with MERLIN using a phase referencing technique to determine accurate astrometric positions. The positions were compared with the…

Astrometry is a powerful technique in astrophysics to measure three-dimensional positions of stars and other astrophysical objects, including exoplanets and the gravitational influence they have on each other. Interferometric astrometry is…

We present a detailed discussion of how to obtain precise stellar photometry in crowded fields using images from multi-conjugate adaptive optics (MCAO) systems, with the intent of informing the scientific development of this key technology…

This paper presents a new strategy for observing faint galaxies with high order natural guide star systems. We have imaged 5 high galactic latitude fields within the isoplanatic patch of bright stars (8.5 < R < 10.3 mag). The fields provide…

Using a portable star tracking system, we are able to obtain the geographical position of the observer, longitude, latitude and North direction. In this work, a new optimization method has been applied to improve accuracy in calculation of…

Because of the recent technological advances, the key technologies needed for precision space optical astrometry are now in hand. The Microarcsecond Astrometry Probe (MAP) mission concept is designed to find 1 Earth mass planets at 1AU…

Astrometry is one of the oldest branches of astronomy which measures the position, the proper motion and parallax of celestial objects. Following the Hipparcos and Gaia missions that have measured several billions of them using global…

In this paper we describe the U-band imaging of the F02 deep field, one of the fields in the VIRMOS Deep Imaging Survey. The observations were done at the ESO/MPG 2.2m telescope at La Silla (Chile) using the 8k x 8k Wide-Field Imager (WFI).…

High precision astrometry requires an accurate geometric distortion solution. In this work, we present an average correction for the Blue Camera of the Large Binocular Telescope which enables a relative astrometric precision of ~15 mas for…

The solar-age open cluster M67 (C0847+120, NGC2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M67 at fainter magnitudes and their properties are not…

We summarize the scientific potential of high contrast optical space imaging for studies of extrasolar planets, debris disks, and planet formation. The unique scientific capabilities offered by a 2-m class optical telescope, the technical…

We report on the first results from a large-scale observing campaign aiming to use astrometric microlensing to detect and place limits on the mass of single objects, including stellar remnants. We used the Hubble Space Telescope to monitor…