Astrometric observation of 1992 RF5, 1988 DX1, 1989 TT3 and other asteroids near the 5:2 resonance with Jupiter

The outer border of the 5:2 jovian mean motion resonance is a prodigious region in our solar system. Numerical simulations show that some bodies (namely 2953 Vyshleslavia) currently orbiting above the resonance have chaotic evolutions with very short dynamical lifetimes of the order of only 10 Myr. Since Vyshleslavia is a member of the Koronis family, such a short dynamical lifetime opens a variety of interesting questions concerning its origin and evolution. We suggest, that such a peculiar orbit might be a result of Yarkovsky effect - a tiny thermal force which cause a slow drift of the semimajor axis.

Several asteroids with semimajor axes just above 2.82 AU were discovered during last ten years. However, their orbits are not determined precisely enough to numerically integrate their orbital evolution in the 5:2 region and determine lifetimes or memberships to the Koronis family.

Hence we are asking for astrometric observations especially of these asteroids: 1992 RF5, 1988 DX1 and 1989 TT3. Other asteroids involved in our calculations, which do not have large orbit uncertainities are (9631), (9990), 1992 DH3, 1988 RY5 and 1996 TE - their observations would be also appreciated, but they are not so critical.

designationopositionmagnitude
1992 RF52000040217.3
1988 DX12000112818.8
1989 TT32001011119.4
1992 DH32001011019.0
1988 RY52000082316.4
1996 TE 2000061118.1
(9631) 2000063017.3
(9990) 1999122617.3

The table lists the asteroid number or its preliminary designation, the date of the next oposition (in YYYYMMDD format) and finally the approximate apparent magnitude during that oposition.

More informations about our reseach, numerical simulations and Yarkovsky effect could be found at our WEB site http://sirrah.troja.mff.cuni.cz/~mira/mp/

Miroslav Broz (mira@sirrah.troja.mff.cuni.cz) and David Vokrouhlicky (vokrouhl@mbox.cesnet.cz)
Institute of Astronomy, Charles University, Prague, Czech Republic

Miroslav Broz, miroslav.broz@email.cz, Dec 22nd 1999