Reference Systems

Asteroid-based tie between Gaia-CRF3 and DE440 shows ~10 mas orientation offset; adding Gaia into orbit solutions reduces it to ~0.2 mas.

AllWISE shows sub-10 mas systematics and sub-0.1 mas yr⁻¹ spin relative to Gaia DR3, making it a robust infrared celestial reference frame.

We pre-evaluated the astrometric performance of the China Space Station Telescope Sky Survey in extending the Gaia Celestial Reference Frame by using a simulated set of sources.

We discovered a new term of secular aberration drift due to the changing line of sight, affecting stellar proper motions measured by Gaia.

We present an updated study on assessing the axes stability of the third generation of the International Celestial Reference Frame (ICRF3).

We determined that current planetary ephemeris reference frames are aligned within 0.4 mas and non-rotating to better than 5 μas/yr.

Using pulsar positions measured independently by timing, VLBI, and Gaia, this paper assesses the orientation consistency between …

We estimated the effect of Galactic aberration on Earth orientation parameters based on geodetic/astrometric very long baseline …

VLBI-based evaluation of ICRF3 stability shows that the axes are stable at the 10–20 μas level over 1979–2020.

Alignment of multiwavelength VLBI–Gaia positions with parsec-scale jets; optical centroids are downstream and polarized, consistent with a core–jet scenario.