Reference : (6478) Gault: physical characterization of an active main-belt asteroid
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/261804
(6478) Gault: physical characterization of an active main-belt asteroid
English
Devogèle, Maxime [Arecibo Observatory, University of Central Florida, HC-3 Box 53995, Arecibo, PR 00612, USA]
Ferrais, Marin [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa) >]
Jehin, Emmanuel mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa) >]
Moskovitz, Nicholas [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA]
Skiff, Brian A. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA]
Levine, Stephen E. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA; Department of Earth, Atmospheric and Planetary Sciences, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA]
Gustafsson, Annika [Department of Astronomy and Planetary Science, Northern Arizona University, PO Box 6010, Flagstaff, AZ 86011, USA]
Farnocchia, Davide [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, USA]
Micheli, Marco [ESA NEO Coordination Centre, Largo Galileo Galilei, 1, I-00044 Frascati (RM), Italy]
Snodgrass, Colin [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ, UK]
Borisov, Galin [Armagh Observatory and Planetarium, College Hill, Armagh BT61 9DG, UK; Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussèe Blvd., BG-1784 Sofia, Bulgaria]
Manfroid, Jean [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO) >]
Moulane, Youssef [Université de Liège - ULiège > > STAR >]
Benkhaldoun, Zouhair [Oukaimeden Observatory, High Energy Physics and Astrophysics Laboratory, Cadi Ayyad University, BP 2390, Marrakech, Morocco]
Burdanov, Artem [Department of Earth, Atmospheric and Planetary Sciences, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA]
Pozuelos, Francisco J. [Space sciences, Technologies & Astrophysics Research (STAR) Institute University of Liège Allée du 6 Août 19, B-4000 Liège, Belgium]
Gillon, Michaël [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Exotic >]
de Wit, Julien [Department of Earth, Atmospheric and Planetary Sciences, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA]
Green, Simon F. [The Open University, Walton Hall, Milton Keynes MK7 6AA, UK]
Bendjoya, Philippe [Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Campus Valrose, F-06304, Nice, France]
Rivet, Jean-Pierre [Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Campus Valrose, F-06304, Nice, France]
Abe, Luy [Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Campus Valrose, F-06304, Nice, France]
Vernet, David [Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Campus Valrose, F-06304, Nice, France]
Chandler, Colin Orion [Department of Astronomy and Planetary Science, Northern Arizona University, PO Box 6010, Flagstaff, AZ 86011, USA]
Trujillo, Chadwick A. [Department of Astronomy and Planetary Science, Northern Arizona University, PO Box 6010, Flagstaff, AZ 86011, USA)]
1-Jul-2021
Monthly Notices of the Royal Astronomical Society
Oxford University Press
505
245
Yes
International
0035-8711
1365-2966
Oxford
United Kingdom
[en] minor planets ; asteroids: individual: (6478) Gault ; Astrophysics - Earth and Planetary Astrophysics
[en] In 2018 December, the main-belt asteroid (6478) Gault was reported to display activity. Gault is an asteroid belonging to the Phocaea dynamical family and was not previously known to be active, nor was any other member of the Phocaea family. In this work, we present the results of photometric and spectroscopic observations that commenced soon after the discovery of activity. We obtained observations over two apparitions to monitor its activity, rotation period, composition, and possible non-gravitational orbital evolution. We find that Gault has a rotation period of P = 2.4929 ± 0.0003 h with a light-curve amplitude of 0.06 magnitude. This short rotation period close to the spin barrier limit is consistent with Gault having a density no smaller than ρ = 1.85 g cm^-3 and its activity being triggered by the YORP (Yarkovsky-O'Keefe-Radzievskii-Paddack) spin-up mechanism. Analysis of the Gault phase curve over phase angles ranging from 0.4° to 23.6° provides an absolute magnitude of H = 14.81 ± 0.04, G1 = 0.25 ± 0.07, and G2 = 0.38 ± 0.04. Model fits to the phase curve find the surface regolith grain size constrained between 100 and 500 $\rm {\mu }$m. Using relations between the phase curve and albedo, we determine that the geometrical albedo of Gault is p[SUB]v[/SUB] = 0.26 ± 0.05 corresponding to an equivalent diameter of $D = 2.8^{+0.4}_{-0.2}$ km. Our spectroscopic observations are all consistent with an ordinary chondrite-like composition (S, or Q-type in the Bus-DeMeo taxonomic classification). A search through archival photographic plate surveys found previously unidentified detections of Gault dating back to 1957 and 1958. Only the latter had been digitized, which we measured to nearly double the observation arc of Gault. Finally, we did not find any signal of activity during the 2020 apparition or non-gravitational effects on its orbit.
Professionals
http://hdl.handle.net/2268/261804
10.1093/mnras/stab1252
https://ui.adsabs.harvard.edu/abs/2021MNRAS.505..245D

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