Investigating ejecta plume and tail of (65803) Didymos binary system

The NASA Double Asteroid Redirection Test (DART) spacecraft was the first Planetary Defence mission to hit an asteroid, specifically the moon of Didymos, Dimorphos 1. This impact altered Dimorphos's orbital parameters and excavating significant amount of material. The resultant was observed through limited ground-based telescopes, and for several months after the impact, the asteroid became the first man-made active asteroid, exhibiting mass loss that manifested as a tail, which changed over time 2.The measurements presented here derive from a unique set of photometric data obtained from the ground over several months covering the period before, during and after the impact, between August 2022 and January 2023. The data set taken in collaboration with ESA at Les Makes Observatory (La Runion) 3, was excellently located to observe the impact and contains more than 8500 images taken over multiple months before and after impact. Another unique data set comes from the TRAPPIST telescopes network 4, two 0.6-m twin telescopes located in Morocco and in Chile. The data from TRAPPIST, contain almost 14 000 images, spanning several months. The images were taken in different filters, for photometric and colour measurements that gave us more information about the asteroid and also the dust composition of the ejecta tail. Here, we present the observations, their analysis and preliminary results on the evolution of ejecta plume and the long-lasting tail.AcknowledgementThis research is funded by the University of Lige and takes place under the COMETA team, and is made possible through TRAPPIST that is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant T.0120.21 and the support and collaboration of the Royal Observatory of Belgium, Les Makes Observatory, and the European Space Agency.zgur Karateking, acknowledges the support of European Unions Horizon 2020 research and innovation program, NEO-MAPP project (grant: 870377) as well as the funding support from the PRODEX program managed by the European Space Agency (ESA) with help of the Belgian Science Policy Office (BELSPO).Reference1 Nancy L. Chabot et al (including Petrescu E.), PSJ 5:49 (24pp), 2024 February 2024;2 Nicholas Moskovitz et al 2024 Planet. Sci. J. 5 35;3 https://www.observatoiredesmakes.com/4 Jehin E. et al, The Messenger, vol. 145, p. 2-6, 2