长周期彗星动力学特性统计研究

Statistical Study of the Dynamical Properties of Long Period Comets

基于JPL(Jet Propulsion Laboratory)和MPC(Minor Planet Center)的彗星观测数据,对长周期彗星(Long Period Comet,LPC)的轨道进行逆向演化,得到其原始轨道,并分析了LPC的观测轨道和原始轨道的动力学特性.研究表明:LPC观测轨道半长轴倒数(1/a)obs和原始轨道半长轴倒数(1/a)ori分布存在显著差异,峰值分别位于(1/a)obs-2×10^(-5)au^(-1)和(1/a)ori-6×10^-(5)au^(-1);大近日点LPC(近日点距离q>3.1 au)和小近日点LPC(近日点距离q≤3.1 au)的原始轨道(1=a)ori峰值位置相同,均位于1×10^(-4)au^(-1);JPL和MPC数据中LPC的原始轨道(1/a)obs峰值没有显著差异,均在1×10^(-4)au^(-1);奥尔特云彗星(Oort cloudcomet)中很多拥有较大的近日点距离(超过50%的奥尔特云彗星q>3.1 au).其对了解长周期彗星和奥尔特云彗星的动力学特性提供了重要信息,也将为未来以长周期彗星为目标的空间任务目标选取提供研究基础.

Based on comet observations from JPL(Jet Propulsion Laboratory)and MPC(Minor Planet Center),the orbits of long period comets(LPC)were reverse-evolved to obtain their original orbits.The dynamic characteristics of LPC observation orbit and original orbit are analyzed.The results show that the distribution of reciprocal of the semi-major axis of LPC observation orbit((1/a)obs)is significantly different from that of the original orbit((1/a)ori),and the peak values are at(1/a)obs-2×10^(−5)au^(−1)and(1/a)ori-6×10^(−5)au^(−1),respectively;large perihelion LPC(perihelion distance q>3.1 au)and small perihelion LPC(perihelion distance q≤3.1 au)have the same peak position of original orbit((1/a)ori),both located at 1×10^(−4)au^(−1);the peak positions of original reciprocal semi-major axis of LPC between JPL and MPC are the same,both at 1×10^(−4)au^(−1).Many Oort cloud comets have large perihelion distances(more than 50%of comets with q>3.1 au).It will provide information to understand the dynamical characteristics of long period comets and Oort cloud comet,and will also provide a research basis for future space missions targeting long period comets.