Photometry of the Didymos System across the DART Impact Apparition

0583318 - ASÚ 2025 RIV US eng J - Journal Article
Moskovitz, N. - Thomas, C. - Pravec, Petr - Scheirich, Peter - Fatka, Petr - Hornoch, Kamil - Kučáková, Hana - Kušnirák, Peter … Total 81 authors
Photometry of the Didymos System across the DART Impact Apparition.
The Planetary Science Journal. Roč. 5, č. 2 (2024), č. článku 35. E-ISSN 2632-3338
R&D Projects: GA ČR(CZ) GA20-04431S; GA ČR(CZ) GA23-04946S
Grant - others:GA MŠk(CZ) LM2015042; GA MŠk(CZ) LM2015085
Institutional support: RVO:67985815
Keywords : near-Earth objects * asteroids * small solar system bodies
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 3.4, year: 2022
Method of publishing: Open access

On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the satellite of binary near-Earth asteroid (65803) Didymos. This demonstrated the efficacy of a kinetic impactor for planetary defense by changing the orbital period of Dimorphos by 33 minutes. Measuring the period change relied heavily on a coordinated campaign of lightcurve photometry designed to detect mutual events (occultations and eclipses) as a direct probe of the satellite's orbital period. A total of 28 telescopes contributed 224 individual lightcurves during the impact apparition from 2022 July to 2023 February. We focus here on decomposable lightcurves, i.e., those from which mutual events could be extracted. We describe our process of lightcurve decomposition and use that to release the full data set for future analysis. We leverage these data to place constraints on the postimpact evolution of ejecta. The measured depths of mutual events relative to models showed that the ejecta became optically thin within the first similar to 1 day after impact and then faded with a decay time of about 25 days. The bulk magnitude of the system showed that ejecta no longer contributed measurable brightness enhancement after about 20 days postimpact. This bulk photometric behavior was not well represented by an HG photometric model. An HG 1 G 2 model did fit the data well across a wide range of phase angles. Lastly, we note the presence of an ejecta tail through at least 2023 March. Its persistence implied ongoing escape of ejecta from the system many months after DART impact.
Permanent Link: https://hdl.handle.net/11104/0353360