VLBI astrometry of radio stars to link radio and optical celestial reference frames – II. 11 radio stars
Year: 2026
Type: article
Abstract: ABSTRACT The alignment between the radio-based International Celestial Reference Frame (ICRF) and the optical Gaia Celestial Reference Frame (Gaia–CRF) is critical for multi-waveband astronomy, yet systematic offsets at the optical bright end ($G \lesssim 13$) limit their consistency. While radio stars offer a potential link between these frames, their utility has been restricted by the scarcity of precise Very Long Baseline Interferometry (VLBI) astrometry. In this study, we present new VLBI astrometry of 11 radio stars using the Very Long Baseline Array (VLBA), expanding the existing sample with positions, parallaxes, and proper motions measured. All 11 radio stars were detected, for 10 of which parallaxes and proper motions can be estimated, achieving median uncertainties better than 0.1 mas and 0.1 mas yr$^{-1}$, respectively. These new samples greatly contribute to the link between ICRF and Gaia-CRF at the optical bright end.
Authors: Jingdong Zhang, Bo Zhang, Shuangjing Xu, Xiaofeng Mai, Mark J Reid, Pengfei Jiang, Wen Chen, Fengchun Shu, Jinling Li, Lang Cui, Xingwu Zheng, Yan Sun, Zhaoxiang Qi
Institutions: Chinese Academy of Sciences, Shanghai Astronomical Observatory, Finnish Geospatial Research Institute, University of Chinese Academy of Sciences, Maanmittauslaitos, Korea Astronomy and Space Science Institute, University of Helsinki, Center for Astrophysics Harvard & Smithsonian, Xinjiang Astronomical Observatory, Yunnan Observatories, Nanjing University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
OpenAlex ID: W4417455758