Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact

• Main Authors: Graykowski, Ariel, Lambert, Ryan A, Marchis, Franck, Cazeneuve, Dorian, Dalba, Paul A, Esposito, Thomas M, Peluso, Daniel O'Conner, Sgro, Lauren A, Blaclard, Guillaume, Borot, Antonin, Malvache, Arnaud, Marfisi, Laurent, Powell, Tyler M, Huet, Patrice, Limagne, Matthieu, Payet, Bruno, Clarke, Colin, Murabana, Susan, Owen, Daniel Chu, Wasilwa, Ronald, Fukui, Keiichi, Goto, Tateki, Guillet, Bruno, Huth, Patrick, Ishiyama, Satoshi, Kukita, Ryuichi, Mitchell, Mike, Primm, Michael, Randolph, Justus, Rivett, Darren A, Ryno, Matthew, Shimizu, Masao, Toullec, Jean-Pierre, Will, Stefan, Yue, Wai-Chun, Camilleri, Michael, Graykowski, Kathy, Janetzke, Ron, Janke, Des, Kardel, Scott, Loose, Margaret, Pickering, John W, Smith, Barton A, Transom, Ian M
• Format: Journal Article
• Language: English
• Published: 09-03-2023
• Subjects: Physics - Earth and Planetary Astrophysics
• DOI: 10.48550/arxiv.2303.05548

On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft
impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a
binary system, it is possible to determine how much the orbit of the satellite
changed, as part of a test of what is necessary to deflect an asteroid that
might threaten Earth with an impact. In nominal cases, pre-impact predictions
of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report
optical observations of Dimorphos before, during and after the impact, from a
network of citizen science telescopes across the world. We find a maximum
brightening of 2.29 $\pm$ 0.14 mag upon impact. Didymos fades back to its
pre-impact brightness over the course of 23.7 $\pm$ 0.7 days. We estimate lower
limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos'
mass depending on the dust size. We also observe a reddening of the ejecta upon
impact.