论文标题
预测飞镖的影响：使用简化模型的Dimorphos的轨道估计
Anticipating the DART impact: Orbit estimation of Dimorphos using a simplified model
论文作者
论文摘要
我们在2003 - 2021年的光曲线中观察到的65803 Didymos二进制系统的成分之间使用了掩体和蚀的时间来估计Dimorphos相对于Didymos的轨道参数。我们采用了加权最小二乘的方法和修改的开普勒轨道模型，以适应非重力力量（例如二进制YORP）的效果，这可能会导致平均运动随时间变化。我们估计，飞镖撞击的那天，在2022年8月26.0 TDB时期的相互轨道时期为11.9214869 \ pm 0.000028 $ 〜H（$1σ$），轨道的平均运动以$ $ 1.0 \ pm 1.0 \ pm 1.0 \ times 10^$ 10^$^$^rad} $ 10^$^rad} $^18} $^{-18} - $（1σ$）。在计划的双小行星重定向测试（DART）任务中，Dimorphos轨道阶段的正式$3σ$不确定性为$ 5.4^\ Circ $。从2022年7月到9月的观察，即飞镖撞击前几个月至几天，应为轨道阶段不确定性提供适度的改进，并将其减少到$ 4.2^\ Circ $。这些结果是使用相对简单的模型生成的，与使用\ citet {Scheirich22}的更复杂模型生成的结果一致，该模型证明了我们方法的可靠性，并为这些关键任务结果增添了信心。
We used the times of occultations and eclipses between the components of the 65803 Didymos binary system observed in its lightcurves from 2003-2021 to estimate the orbital parameters of Dimorphos relative to Didymos. We employed a weighted least-squares approach and a modified Keplerian orbit model in order to accommodate the effects from non-gravitational forces such as Binary YORP that could cause a linear change in mean motion over time. We estimate that the period of the mutual orbit at the epoch 2022 September 26.0 TDB, the day of the DART impact, is $11.9214869 \pm 0.000028$~h ($1σ$) and that the mean motion of the orbit is changing at a rate of $(5.0\pm 1.0)\times 10^{-18}$~rad s$^{-2}$ $(1σ$). The formal $3σ$ uncertainty in orbital phase of Dimorphos during the planned Double Asteroid Redirection Test (DART) mission is $5.4^\circ$. Observations from July to September 2022, a few months to days prior to the DART impact, should provide modest improvements to the orbital phase uncertainty and reduce it to about $4.2^\circ$. These results, generated using a relatively simple model, are consistent with those generated using the more sophisticated model of \citet{scheirich22}, which demonstrates the reliability of our method and adds confidence to these mission-critical results.
