Asteroid 2012 XE133: a transient companion to Venus
Abstract
Apart from Mercury that has no known co-orbital companions, Venus remains as the inner planet that hosts the smallest number of known co-orbitals (two): (322756) 2001 CK32 and 2002 VE68. Both objects have absolute magnitudes 18 < H < 21 and were identified as Venus co-orbitals in 2004. Here, we analyse the orbit of the recently discovered asteroid 2012 XE133 with H = 23.5 mag to conclude that it is a new Venus co-orbital currently following a transitional trajectory between Venus' Lagrangian points L5 and L3. The object could have been a 1:1 librator for several thousand years and it may leave the resonance with Venus within the next few hundred years, after a close encounter with the Earth. Our calculations show that its dynamical status as co-orbital, as well as that of the two previously known Venus co-orbitals, is controlled by the Earth-Moon system with Mercury playing a secondary role. The three temporary co-orbitals exhibit resonant (or near-resonant) behaviour with Mercury, Venus and the Earth and they follow rather chaotic but similar trajectories with e-folding times of the order of 100 yr. Out of the three co-orbitals, 2012 XE133 currently follows the most perturbed path. An actual collision with the Earth during the next 10 000 yr cannot be discarded; an encounter at 0.005 au may take place in 2028, but even closer encounters are possible within that time frame. Extrapolation of the number distribution of Venus co-orbitals as a function of the absolute magnitude suggests that dozens of objects similar to 2012 XE133 could be transient companions to Venus. Some additional objects that were or will be transient co-orbitals to Venus are also briefly discussed.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2013
- DOI:
- arXiv:
- arXiv:1303.3705
- Bibcode:
- 2013MNRAS.432..886D
- Keywords:
-
- celestial mechanics;
- minor planets;
- asteroids: general;
- asteroids: individual: 2012 XE<SUB>133</SUB>;
- asteroids: individual: (322756) 2001 CK<SUB>32</SUB>;
- asteroids: individual: 2002 VE<SUB>68</SUB>;
- planets and satellites: individual: Venus;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 9 pages, 9 figures, 3 embedded animations, 1 table, abstract abridged, matches version published in MNRAS