2013/01/03 by Oleg Titov, Titov, Oleg
Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #astro-ph.CO #astro-ph.EP #astro-ph.GA #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1301.0364
Proceedings of the "Journees-2011" meeting hold in Vienna University of Technology, 19-21 September, 2011
arxiv created 2013/01/03 · arxiv updated 2013/11/06
The centrifugial acceleration of the Solar system, resulting from the gravitational attraction of the Galaxy centre, causes a phenomenon known as 'secular aberrration drift'. This acceleration of the Solar system barycentre has been ignored so far in the standard procedures for high-precision astrometry. It turns out that the current definition of the celestial reference frame as epochless and based on the assumption that quasars have no detectable proper motions, needs to be revised. In the future, a realization of the celestial reference system (realized either with VLBI, or GAIA) should correct source coordinates from this effect, possibly by providing source positions together with their proper motions. Alternatively, the galactocentric acceleration may be incorporated into the conventional group delay model applied for VLBI data analysis.