Assessing the detection of the Yarkovsky effect using the Gaia DR3 and FPR catalogues

¹ Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University, Słoneczna 36, 60-286 Poznań, Poland
² Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías (IUFACyT), Universidad de Alicante, Ctra. San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Alicante, Spain
³ Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS 15, Cambridge, MA, 02138, USA

^★ Corresponding author; karolinadziadura36@gmail.com

Received: 9 December 2023
Accepted: 5 November 2024

Abstract

Aims. The primary objective of this study was to use the newest Gaia Focused Product Release (FPR) catalogue, which contains ultra-precise asteroid astrometry spanning 66 months, to detect the Yarkovsky effect. This non-gravitational acceleration affects the orbits of small asteroids. Moreover, we examined close approaches of near-Earth asteroids by comparing orbits calculated based on Gaia data.

Methods. We used the conventional least-squares orbit computation method, which is available in the OrbFit software (version developed at the MPC). We used the latest Gaia FPR, complemented by data from the Minor Planet Center and radar astrometry from the Jet Propulsion Laboratory. We fitted the orbital parameters for 446 eear-Earth asteroids, including the additional non-gravitational transverse acceleration, to model the Yarkovsky effect. Furthermore, we compared the results obtained using different datasets: the Gaia FPR, and the previous Gaia Data Release 3 (DR3).

Results. We detected a robust Yarkovsky effect in 43 NEAs. As expected, we found an improvement in the orbital element uncertainty and in the signal-to-noise ratio of the Yarkovsky effect detections when we used the current Gaia FPR with twice the observing arc compared to the Gaia DR3 catalogue. We also found nine additional reliable detections of the Yarkovsky effect based on the new Gaia FPR catalogue.

Conclusions. It can be important to include the Yarkovsky effect in the force model to reliably estimate close-approach distances of near-Earth asteroids. Several of the detected Yarkovsky drifts already have a signal-to-noise ratio greater than 10, which is high enough for their Yarkovsky effect to be included in their reliable long-term orbital evolution, close approach, and Earth-impact analysis. The final Gaia catalogue may provide a much higher number of detections with a high signal-to-noise ratio of the Yarkovsky effect. This would allow us to include the effect more broadly in routine close-approach and impact analyses of these objects.