Title: Thermal and Optical Characterization of Near-Earth Objects: Science Commissioning of the Recently Upgraded Mid-Infrared Camera MIRSI on the NASA Infrared Telescope Facility Show Chinese title

Title: 近地天体的热学和光学特性：NASA红外望远镜设施上 recently 升级的中红外相机 MIRSI 的科学调试

Abstract: Mid-infrared (mid-IR) observations of Near-Earth Objects (NEOs) have historically been a valuable tool for understanding their physical properties. However, the current state of mid-IR instruments on ground-based telescopes places several limitations on performing thermal characterization of NEOs. The complexity of maintaining these instruments in operational conditions on telescopes has led to their decommissioning. Here, we present the first science commissioning observations out to 12.5 microns from the upgraded Mid-Infrared Spectrograph and Imager (MIRSI) at the NASA-IRTF. We obtained 42 observations of 31 NEOs and derived their diameters and albedos. Since MIRSI allows simultaneous optical observations with its MIRSI Optical Camera (MOC), we were able to determine the absolute magnitude for most of the targets at the time of the thermal acquisition. We present ejecta characterization for the Didymos system from observations made 11 hours and 9 days after the Double Asteroid Redirection Test (DART) impact. We present albedo and size measurements for (98943) Torifune 2001 CC21, the fly-by target of the Japanese Extended Hayabusa2 Mission. We also highlight several applications that the MIRSI system will provide for future airless body characterization, such as constraining thermal inertia from simultaneous optical and thermal lightcurves. This work also demonstrates the importance of having MIRSI as an available rapid-response instrument for planetary defense purposes. Show Chinese abstract

Abstract: 近地天体（NEOs）的中红外（mid-IR）观测在历史上一直是了解它们物理特性的宝贵工具。然而，地面望远镜上中红外仪器的现状对NEOs的热特性表征施加了若干限制。维持这些仪器在望远镜上的运行条件的复杂性导致了它们被退役。在这里，我们展示了来自NASA-IRTF升级后的中红外光谱仪和成像仪（MIRSI）的首次科学调试观测，范围达到12.5微米。我们获得了31颗近地天体的42次观测，并推导出了它们的直径和反照率。由于MIRSI允许与其中红外光学相机（MOC）同时进行光学观测，我们能够在热获取时为大多数目标确定绝对星等。我们从双小行星重定向测试（DART）撞击后11小时和9天的观测中展示了Didymos系统的喷发特征。我们展示了（98943）Torifune 2001 CC21的小行星的反照率和尺寸测量结果，这是日本延长的隼鸟2号任务的飞越目标。我们还强调了MIRSI系统将为未来无大气天体的特征化提供的一些应用，例如通过同时的光学和热光变曲线来约束热惯量。这项工作也证明了拥有MIRSI作为一种可用的快速响应仪器用于行星防御的重要性。