Age estimation of Trans-Neptunian Object pairs in close orbits

Abstract

A search for pairs of trans-Neptunian objects in close orbits with semi-major axes greater than 30 AU has been conducted. The proximity of the orbital pairs was determined using Kholshevnikov metrics. A total of 46 pairs of trans-Neptunian objects with metric values below 0.1 AU${}^{1/2}$ were identified. The dynamical evolution of these pairs was investigated over the past 10 Myr using numerical methods based on their nominal orbits. The formation epochs of the trans-Neptunian object pairs were determined using the method of nodal and apsidal convergence analysis, as well as the orbital convergence method. For the pairs 2003 QX90 – 2000 ON67, 2005 CE81 – 2003 QY90, 2013 TG229 – 2009 YK32, 2013 UN17 – 2003 QX90 and 2019 QL111 – 2015 GF59, a probabilistic evolution study was conducted over a 2-Myr interval. For the pairs 2003 QX90 – 2000 ON67, 2013 TG229 – 2009 YK32, 2013 UN17 – 2003 QX90 and 2019 QL111 – 2015 GF59, their ages were estimated, and the fraction of formation orbits within the studied interval was calculated. The masses of trans-Neptunian objects that allow for their formation were determined using MOID analysis. The ages of the remaining 42 pairs exceed 10 Myr.