000006236 001__ 6236
000006236 005__ 20230127122449.0
000006236 0247_ $$2DOI$$aA&A
000006236 037__ $$aSCART-2023-0098
000006236 100__ $$aBaland, Rose-Marie
000006236 245__ $$aRelativistic contributions to the rotation of Mars 
000006236 260__ $$c2023
000006236 500__ $$aInSight contribution ICN 304
000006236 520__ $$aContext: The orientation and rotation of Mars, which can be described by a set of Euler angles, is estimated from radioscience data and is then used to infer Mars internal properties. The data are analyzed using a modeling expressed within the Barycentric Celestial Reference System (BCRS). Aims: We provide new and more accurate (to the 0.1 mas level) estimations of the relativistic corrections to be included in the BCRS model of the orientation and rotation of Mars to avoid a misinterpretation of the data. Methods: There are two types of relativistic contributions in Mars rotation and orientation: (i) those that directly impact the Euler angles and (ii) those resulting from the time transformation between a local Mars reference frame and BCRS. The former correspond essentially to the geodetic effect. We compute them assuming that Mars evolves on a Keplerian orbit. As for the latter, we compute the effect of the time transformation and compare the rotation angle corrections obtained using realistic orbits as described by ephemerides. Results: The relativistic correction in longitude comes mainly from the geodetic effect and results in the geodetic precession (6.754mas/yr) and the geodetic annual nutation (0.565 mas amplitude). For the rotation angle, the correction is dominated by the effect of the time transformation. The main annual, semi-annual, and ter-annual terms have amplitudes of 166.954 mas, 7.783 mas, and 0.544mas, respectively. The amplitude of the annual term differs by about 9 mas from the estimate usually considered by the community. We identify new terms at the Mars-Jupiter and Mars-Saturn synodic periods (0.567 mas and 0.102 mas amplitude) that are relevant considering the current level of uncertainty of the measurements, as well as a contribution to the rotation rate (7.3088 mas/day). There is no significant correction that applies to the obliquity. 
000006236 594__ $$aNO
000006236 6531_ $$aastrometry
000006236 6531_ $$aPlanets and satellites: Mars
000006236 6531_ $$aRelativistic processes
000006236 6531_ $$aReference systems
000006236 700__ $$aHees, Aurélien
000006236 700__ $$aYseboodt, Marie
000006236 700__ $$aBourgoin, Adrien
000006236 700__ $$aLe Maistre, Sébastien
000006236 773__ $$pAstronomy & Astrophysics$$y2023
000006236 8560_ $$frose-marie.baland@observatoire.be
000006236 8564_ $$s2570657$$uhttp://publi2-as.oma.be/record/6236/files/Baland_aa_2023.pdf
000006236 8564_ $$s3131$$uhttp://publi2-as.oma.be/record/6236/files/Baland_aa_2023.gif?subformat=icon$$xicon
000006236 8564_ $$s3767$$uhttp://publi2-as.oma.be/record/6236/files/Baland_aa_2023.jpg?subformat=icon-180$$xicon-180
000006236 905__ $$aaccepted to be published in
000006236 980__ $$aREFERD