Precise Astrometry of Visual Binaries with Adaptive Optics. A Way for Finding Exoplanets?

TL;DR

This study demonstrates that high-precision astrometry using adaptive optics on large telescopes can achieve sub-milliarcsecond accuracy, enabling the detection of exoplanets through their astrometric signals.

Contribution

The paper provides an analysis of astrometric stability and systematic effects in AO observations, showing potential for exoplanet detection via precise astrometry.

Findings

Achieved astrometric precision better than 1 milliarcsecond.

Systematic effects like atmospheric refraction can be managed for accurate measurements.

Potential to detect planetary-mass objects through astrometric signals.

Abstract

We present the results of our study of astrometric stability of 200-in Hale (Mt. Palomar) and 10-m Keck II (Mauna Kea) telescopes, both with Adaptive Optics (AO) facilities. A group of nearby visual binaries and multiples was observed in near infrared, relative separations and position angles measured. We have also checked the influence of some systematic effects (e.g. atmospherical refraction, varying plate scale factor) on result and precision of astrometric measurements. We conclude that in visual binaries astrometrical observations it is possible to achieve much better precision than 1 miliarcsecond, which in many cases allows detection of the astrometrical signal produced by planetary-mass object.