Bibcode
Pravec, P.; Fatka, P.; Vokrouhlický, D.; Scheirich, P.; Ďurech, J.; Scheeres, D. J.; Kušnirák, P.; Hornoch, K.; Galád, A.; Pray, D. P.; Krugly, Yu. N.; Burkhonov, O.; Ehgamberdiev, Sh. A.; Pollock, J.; Moskovitz, N.; Thirouin, A.; Ortiz, J. L.; Morales, N.; Husárik, M.; Inasaridze, R. Ya.; Oey, J.; Polishook, D.; Hanuš, J.; Kučáková, H.; Vraštil, J.; Világi, J.; Gajdoš, Š.; Kornoš, L.; Vereš, P.; Gaftonyuk, N. M.; Hromakina, T.; Sergeyev, A. V.; Slyusarev, I. G.; Ayvazian, V. R.; Cooney, W. R.; Gross, J.; Terrell, D.; Colas, F.; Vachier, F.; Slivan, S.; Skiff, B.; Marchis, F.; Ergashev, K. E.; Kim, D.-H.; Aznar, A.; Serra-Ricart, M.; Behrend, R.; Roy, R.; Manzini, F.; Molotov, I. E.
Referencia bibliográfica
Icarus, Volume 333, p. 429-463.
Fecha de publicación:
11
2019
Revista
Número de citas
67
Número de citas referidas
62
Descripción
We studied a sample of 93 asteroid pairs, i.e., pairs of genetically
related asteroids that are on highly similar heliocentric orbits. We
estimated times elapsed since separation of pair members (i.e., pair
age) that are between 7 × 103 yr and a few
106 yr. With photometric observations, we derived the
rotation periods P1 for all the primaries (i.e., the larger
members of asteroid pairs) and a sample of secondaries (the smaller pair
members). We derived the absolute magnitude differences of the studied
asteroid pairs that provide their mass ratios q. For a part of the
studied pairs, we refined their WISE geometric albedos and collected or
estimated their taxonomic classifications. For 17 asteroid pairs, we
also determined their pole positions. In two pairs where we obtained the
spin poles for both pair components, we saw the same sense of rotation
for both components and constrained the angles between their original
spin vectors at the time of their separation. We found that the
primaries of 13 asteroid pairs in our sample are actually binary or
triple systems, i.e., they have one or two bound, orbiting secondaries
(satellites). As a by-product, we found also 3 new young asteroid
clusters (each of them consisting of three known asteroids on highly
similar heliocentric orbits). We compared the obtained asteroid pair
data with theoretical predictions and discussed their implications. We
found that 86 of the 93 studied asteroid pairs follow the trend of
primary rotation period vs mass ratio that was found by Pravec et al.
(2010). Of the 7 outliers, 3 appear insignificant (may be due to our
uncertain or incomplete knowledge of the three pairs), but 4 are high
mass ratio pairs that were unpredicted by the theory of asteroid pair
formation by rotational fission. We discuss a (remotely) possible way
that they could be created by rotational fission of flattened parent
bodies followed by re-shaping of the formed components. The 13 asteroid
pairs with binary primaries are particularly interesting systems that
place important constraints on formation and evolution of asteroid
pairs. We present two hypotheses for their formation: The asteroid pairs
having both bound and unbound secondaries could be "failed asteroid
clusters", or they could be formed by a cascade primary spin fission
process. Further studies are needed to reveal which of these two
hypotheses for formation of the paired binary systems is real.
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