VLBI astrometry of radio stars to link radio and optical celestial reference frames III: 11 radio stars
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
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<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, reaching a precision level of <1% in the best cases. These new samples greatly contribute to the link between ICRF and Gaia-CRF at the optical bright end.
