ecc7917f-110b-4434-8fed-80653a13917d urn:uuid eng UTF-8 nonGeographicDataset nonGeographicDataset 2025-10-16T19:35:16 creation ISO 19115 2016 The Secular Aberration Drift and Future Challenges for VLBI Astrometry ecc7917f-110b-4434-8fed-80653a13917d The centrifugial acceleration of the Solar system, resulting from the gravitational attraction of the Galaxy centre, causes a phenomenon known as 'secular aberration 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. Presented at the Journees 2011 19-21 September, Vienna, Austria. {"type": "Polygon", "coordinates": [[[112.92, -54.75], [159.11, -54.75], [159.11, -9.2402], [112.92, -9.2402], [112.92, -54.75]]]} 112.92 159.11 -54.75 -9.2402 Earth Sciences External Publication Published_External geodesy Link to conference proceedings documentDigital Link to conference proceedings PDF Link to paper documentDigital Link to paper HTML Unnamed resource documentDigital HTML