000007527 001__ 7527
000007527 005__ 20250204105339.0
000007527 037__ $$aCTALK-2025-0064
000007527 100__ $$aIvantsov, Anatoliy
000007527 245__ $$aAstrometric bias due to overlapping image profiles in the focal plane and its removal in the positions of near-Earth asteroids
000007527 260__ $$c2022
000007527 269__ $$c2022-08-04
000007527 520__ $$aBoth astrometric and photometric data of high accuracy provided by the Gaia catalog, its completeness to 21 mag allow evaluating the closeness of past astrometric positions of asteroids to the stars in the focal plane. In case the corresponding image profiles are overlapping, there is a photocenter bias shifting the positions measured towards each other. By correlating astrometric measurements of near-Earth asteroids collected at the IAU Minor Planet Center with the Gaia EDR3 catalog we identified 460,149 asteroid positions as of November 15, 2021, that had been measured within 9'' to stellar images, and thus, are likely affected by the photocenter bias to a varying degree. Assuming image FWHM constant for each observatory all year round, we have fitted the differences (O−C) in astrometric measurements of near-Earth asteroids. After doing that we recalculated the bias values and demonstrate the corresponding statistics. The identified measurements can be further rejected or down-weighted in the orbital fitting process for improving the overall orbital propagation. We emphasize the need of supplying the image FWHM each time the astronomers are submitting their astrometric measurements to the IAU Minor Plane Center.
000007527 594__ $$aNO
000007527 6531_ $$anear-Earth asteroids
000007527 6531_ $$aasteroids
000007527 6531_ $$aphotocenter bias
000007527 6531_ $$aephemerides
000007527 6531_ $$aorbital fitting
000007527 700__ $$aEggl, Siegfried
000007527 700__ $$aHestroffer, Daniel
000007527 773__ $$tXXXI IAU General Assembly Focus Meeting 10 Synergy of Small Telescopes, and Large Surveys for Solar System & Exoplanetary Bodies Research, Busan, Republic of Korea
000007527 8560_ $$fanatoliy.ivantsov@ksb-orb.be
000007527 85642 $$ahttps://www.iauga2022.org
000007527 8564_ $$s2848959$$uhttp://publi2-as.oma.be/record/7527/files/iaufm10_ivantsov_slides.pdf
000007527 8564_ $$s10358$$uhttp://publi2-as.oma.be/record/7527/files/iaufm10_ivantsov_slides.gif?subformat=icon$$xicon
000007527 8564_ $$s13739$$uhttp://publi2-as.oma.be/record/7527/files/iaufm10_ivantsov_slides.jpg?subformat=icon-180$$xicon-180
000007527 906__ $$aContributed
000007527 980__ $$aCTALKCONT