论文标题
低活动性彗星P/2016 ba $ _ {14} $的近红外光谱在其2016年近距离接近方法中
Near-Infrared Spectroscopy Of The Nucleus Of Low-Activity Comet P/2016 BA$_{14}$ During Its 2016 Close Approach
论文作者
论文摘要
近地球彗星P/2016 ba $ _ {14} $（Panstarrs）是一个缓慢改头的近调对象，可能是252p/线性的动态双胞胎，最近被证明具有与其他彗星非常相似的中膜谱。 Ba $ _ {14} $最近还选择了ESA的\ textit {Comet Interceptor}的备份目标之一，因此对BA $ _ {14} $的现代属性的更清晰了解不仅会改善我们对彗星的理解，还可以帮助计划潜在的太空人访问。我们介绍了BA $ _ {14} $在2016年接近NASA红外望远镜设施的ba $ _ {14} $的观察结果，这两种设施都与对其核的直接观察一致。 Ba $ _ {14} $的反射率类似于67p/churyumov-gerasimenko，尽管具有很高的相位。热发射在更长的波长下污染了反射率频谱，我们使用新的马尔可夫链蒙特卡洛热建模代码校正了反射光谱。这些模型表明$ ba_ {14} $的可见几何反照率为$ p_v = 0.01-0.03 $，与雷达观测一致，其光束参数对于NEOS在其几何形状中观察到的典型，并且其反射频谱在H和k band中是红色和线性的。尽管它具有中红外的怪异，但它看起来非常像“正常”的彗星核。由于对象的活动减少，因此细粒的缓慢损失可能有助于调和一些证据，我们讨论了其他可能性。超过ba $ _ {14} $的航天器飞行比以更活跃的目标更接近核，我们重点介绍了一些科学问题，这些问题可以通过访问（几乎 - ）休眠的彗星来解决。
The Near-Earth Comet P/2016 BA$_{14}$ (PanSTARRS) is a slow-rotatating nearly-dormant object, a likely dynamical twin of 252P/LINEAR, and was recently shown to have a mid-infrared spectrum very dissimilar to other comets. BA$_{14}$ also recently selected one of the back-up targets for the ESA's \textit{Comet Interceptor}, so a clearer understanding of BA$_{14}$'s modern properties would not just improve our understanding of how comets go dormant, but could also aid planning for a potential spacecraft visit. We present observations of BA$_{14}$ taken on two dates during its 2016 Earth close approach with the NASA Infrared Telescope Facility, both of which are consistent with direct observations of its nucleus. The reflectance spectrum of BA$_{14}$ is similar to 67P/Churyumov-Gerasimenko, albeit highly phase-reddened. Thermal emission contaminates the reflectance spectrum at longer wavelengths, which we correct with a new Markov Chain Monte Carlo thermal modeling code. The models suggest $BA_{14}$'s visible geometric albedo is $p_V=0.01-0.03$, consistent with radar observations, its beaming parameter is typical for NEOs observed in its geometry, and its reflectrance spectrum is red and linear throughout H and K band. It appears very much like a "normal" comet nucleus, despite its mid-infrared oddities. A slow loss of fine grains as the object's activity diminished might help to reconcile some of the lines of evidence, and we discuss other possibilities. A spacecraft flyby past BA$_{14}$ could get closer to the nucleus than with a more active target, and we highlight some science questions that could be addressed with a visit to a (nearly-)dormant comet.
