Active asteroids have received lots of attention since they were discovered.311P/PANSTARRS is one of the most interesting active asteroids in China recently and one of the targets of Tianwen-2.Because of its small size of about 400 m,the Yarkovsky effect may have a significantly influence on its long-term dynamics.This paper discussed the changes in the long-term motion of 311P/PANSTARRS caused by the Yarkovsky effect.By assuming different surface compositions,this simulation introduced the semi-major axis drift by propagating orbits of orbital clones,and the effects of other factors such as close encounters,meteoroid impacts and YORP effect on the orbit evolution of 311P/PANSTARRS were also discussed.Additionally,we estimated the time scale for 311P/PANSTARRS to reach its rotation period of splitting limit.The results of the simulations show that the Yarkovsky effect may cause 311P/PANSTARRS to exit from the resonance region faster when compared to a purely gravitational model.311P/PANSTARRS will leave the current resonance region after roughly 10 Myr and have a chance to become a Mars-crossing asteroid through ν6 secular resonance due to the diurnal Yarkovsky effect if its surface is covered by a re-golith layer.It is concluded that 311P/PANSTARRS is stable at least 10 Myr time scale even if taking the Yarkovsky effect and the YORP effect into account.Furthermore,the YORP effect may not significantly affect the semi-major axis drift of 311P/PANSTARRS.
维普
万方数据