Recent formation and likely cometary activity of near-Earth asteroid pair 2019 PR2-2019 QR6
Author
Fatka, P.Moskovitz, N.A.
Pravec, P.
Micheli, M.
Devogèle, M.
Gustafsson, A.
Kueny, J.
Skiff, B.
Kušnirák, P.
Christensen, E.
Ries, J.
Brucker, M.
Mcmillan, R.
Larsen, J.
Mastaler, R.
Bressi, T.
Affiliation
Wyant College of Optical Sciences, University of ArizonaThe University of Arizona, Lunar and Planetary Laboratory
Issue Date
2022
Metadata
Show full item recordPublisher
Oxford University PressCitation
Fatka, P., Moskovitz, N. A., Pravec, P., Micheli, M., Devogèle, M., Gustafsson, A., Kueny, J., Skiff, B., Kušnirák, P., Christensen, E., Ries, J., Brucker, M., Mcmillan, R., Larsen, J., Mastaler, R., & Bressi, T. (2022). Recent formation and likely cometary activity of near-Earth asteroid pair 2019 PR2-2019 QR6. Monthly Notices of the Royal Astronomical Society.Rights
Copyright © 2021 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Asteroid pairs are genetically related asteroids that recently separated (<few million years), but still reside on similar heliocentric orbits. A few hundred of these systems have been identified, primarily in the asteroid main belt. Here, we studied a newly discovered pair of near-Earth objects (NEOs): 2019 PR2 and 2019 QR6. Based on broad-band photometry, we found these asteroids to be spectrally similar to D-types, a type rare amongst NEOs. We recovered astrometric observations for both asteroids from the Catalina Sky Survey from 2005, which significantly improved their fitted orbits. With these refinements we ran backwards orbital integrations to study formation and evolutionary history. We found that neither a pure gravitational model nor a model with the Yarkovsky effect could explain their current orbits. We thus implemented two models of comet-like non-gravitational forces based on water or CO sublimation. The first model assumed quasi-continuous, comet-like activity after separation, which suggested a formation time of the asteroid pair $300^{+120}_{-70}$ yr ago. The second model assumed short-term activity for up to one heliocentric orbit (∼13.9 yr) after separation, which suggested that the pair formed 272 ± 7 yr ago. Image stacks showed no activity for 2019 PR2 during its last perihelion passage. These results strongly argue for a common origin that makes these objects the youngest asteroid pair known to date. Questions remain regarding whether these objects derived from a parent comet or asteroid, and how activity may have evolved since their separation. © 2021 The Author(s).Note
Immediate accessISSN
0035-8711Version
Final published versionae974a485f413a2113503eed53cd6c53
10.1093/mnras/stab3719