Giovedì 21 Marzo 2019, ore 11:00

Osservatorio Astrofisico di Torino, Sala Seminari di Villa Magliola

Gaia astrometry potential for testing post-Newtonian gravity

Dr. Alexey Butkevich

The Central Astronomical Observatory of the Russian Accademy of Sciences

Pulkovo, Russia

Abstract

High-precision astrometry offers good potential for performing various relativity tests. This talk addresses the problem of estimating the parameter $\gamma$ of the parametrized post-Newtonian formalism (PPN) from the Gaia astrometric data. Due to the strong correlation with the stellar parallaxes, there are significant complexities in practical implementation of this task. Global shift in the Gaia parallaxes originating from the instability of the basic angle between the two telescopes makes the subject especially topical. The talk gives an overview of two different strategies for dealing with this difficulty, reports on the results obtained so far, mentions some open question and outlines future steps.