PRECISION ASTROMETRY WITH ADAPTIVE OPTICS

Precision Astrometry with Adaptive Optics

We investigate the limits of ground-based astrometry with adaptive optics using the core of the Galactic globular cluster M5. Adaptive optics systems provide near diffraction-limit imaging with the world’s largest telescopes. The substantial improvement in both resolution and signal-to-noise ratio enables high-precision astrometry from the ground. We describe the dominant systematic errors that...

High Precision Differential Astrometry

While conventional imaging in VLBI provides information only about the relative position between different features of a given source, phase-referenced observations can provide precise positional information with respect to an external reference. The use of differential techniques relies on the fact that most of the instrumental and propagation effects are common for radio sources sufficiently ...

Precision Geodesy and Astrometry Via

Impact of the Atmospheric Refraction on the Precise Astrometry with Adaptive Optics in Infrared

Context. We study the impact of the atmospheric differential chromatic refraction on the measurements and precision of relative astrometry. Specifically, we address the problem of measuring the separations of close pairs of binary stars with adaptive optics in the J and K bands. Aims. We investigate the influence of weather conditions, zenithal distance, star’s spectral type and observing wavel...

High-precision Timing of Millisecond Pulsars and Precision Astrometry

We present the technique of long-term, high-precision timing of millisecond pulsars as applied to precision astrometry. We provide a tutorial on pulsars and pulsar timing, as well as up-to-date results of long-term timing observations of two millisecond pulsars, PSRs B1855+09 and B1937+21. We consider the feasibility of tying the extragalactic and optical reference frames to that deened by sola...