论文标题
Active CentaR P/2019 LD2的同时多波长和预发现观察结果（Atlas
Contemporaneous Multi-Wavelength and Precovery Observations of Active Centaur P/2019 LD2 (ATLAS
论文作者
论文摘要
Gateway Centaur and Jupiter Co-Orbital P/2019 LD2（Atlas）（Sarid等人，2019年）提供了第一个机会，可以观察太阳系从半人物轨道迁移到木星轨道到木星家族彗星（JFC）从现在开始的四十年（Kareta等，2020; Hsieh等人。网关过渡区域超出了水冰可以为彗星活动供电，而在那里的昏迷中，昏迷的产生与所有半人马一样众所周知。我们提出了从2020年7月2-4日开始的LD2的同时多波长观测值：双子座北看到的成像，NASA IRTF近红外光谱和ARO SMT毫米毫米波谱光谱学。预发现DECAM图像将核的有效半径限制在<= 1.2 km，并且在档案Catalina Sky调查观察中没有看到大爆发。 LD2的昏迷的g'-r'= 0.70 +/- 0.07，r'-i'= 0.26 +/- 0.07，灰尘生产速率约为10-20 kg/s，并且V〜0.6-3.3 m/s之间的流速速度。我们未检测到2020年7月2日至3日朝LD2的CO，Q（co）<4.4 * 10^27 mol/s（<200 kg/s）的3-sigma上限。近红外光谱显示出水冰在1-10％水平的证据，具体取决于晶粒尺寸。空间概况和档案数据与持续活动一致。证据支持以下假设：LD2是将成为典型的jfc的典型小精子，因此了解这两个人群之间的过渡至关重要。最后，我们讨论了在社区范围内进行长期基线监测工作的潜在策略。
Gateway Centaur and Jupiter co-orbital P/2019 LD2 (ATLAS) (Sarid et al. 2019) provides the first opportunity to observe the migration of a Solar System small body from a Centaur orbit to a Jupiter Family Comet (JFC) four decades from now (Kareta et al., 2020; Hsieh et al. 2020). The Gateway transition region is beyond where water ice can power cometary activity, and coma production there is as poorly understood as in all Centaurs. We present contemporaneous multi-wavelength observations of LD2 from 2020 July 2-4: Gemini-North visible imaging, NASA IRTF near-infrared spectroscopy, and ARO SMT millimeter-wavelength spectroscopy. Precovery DECam images limit the nucleu's effective radius to <=1.2 km and no large outbursts were seen in archival Catalina Sky Survey observations. LD2's coma has g'-r'=0.70+/-0.07, r'-i'=0.26+/-0.07, a dust production rate of ~10-20 kg/s, and an outflow velocity between v~0.6-3.3 m/s. We did not detect CO towards LD2 on 2020 July 2-3, with a 3-sigma upper limit of Q(CO) < 4.4 * 10^27 mol/s (<200 kg/s). Near-infrared spectra show evidence for water ice at the 1-10% level depending on grain size. Spatial profiles and archival data are consistent with sustained activity. The evidence supports the hypothesis that LD2 is a typical small Centaur that will become a typical JFC, and thus it is critical to understanding the transition between these two populations. Finally, we discuss potential strategies for a community-wide, long baseline monitoring effort.
