Galactic Aberration in VLBI Analysis:

• Main Authors: Macmillan, D. S., Fey, A. L., Gipson, J. M., Gordon, David, Jacobs, Christopher S., Krásná, H., Lambert, Sébastien, Ma, Chopo, Malkin, Z., Titov, O. A., Wang, Guangli, Xu, Minghui, Zacharias, Norbert
• Other Authors: Observatoire de Paris, Université Paris sciences et lettres (PSL)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2018
• Subjects: [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; Longyearbyen; Milky Way; Norway
• Online Access: https://hal.archives-ouvertes.fr/hal-03804304

International audience The IVS Working Group on Galactic Aberration (WG8) was established to investigate issues related to incorporating the effect of galactic aberration in IVS analysis. Secular aberration drift is caused by the acceleration of the Solar System barycenter. It is mainly due to the rotation of the barycenter about the center of the Milky Way galaxy. Studies made by working group members have shown that aberration can be estimated from VLBI geodetic data. The VLBI estimates of the aberration amplitude are in the range 5.1 to 6.4 ?as/yr. These estimates are close to independent estimates of 4.8 to 5.4 ?as/yr that were derived from astrometric measurements of proper motions and parallaxes of masers in the Milky Way galaxy. For the recommended aberration constant, a geodetic value 5.8 ?as/yr based on data until May 2018 was chosen by the Working Group in order to be consistent with geodetic VLBI applications, specifically for the generation of the ICRF3 solution. In this paper, we discuss the investigation of the Working Group and its findings.