标题： 使用10.4米大加那利望远镜和两米双筒望远镜评估星际彗星3I/ATLAS 显示英文标题

标题： Assessing interstellar comet 3I/ATLAS with the 10.4 m Gran Telescopio Canarias and the Two-meter Twin Telescope

摘要： 上下文。 行星系统中小型天体的形成和演化理论预测，它们可能在任何时候逃逸到星际空间。 在对这两个外来者——1I/2017 U1（奥陌陌）和2I/Borisov进行表征后，提出的问题比解答的问题更多。 评估最近发现的星际彗星3I/ATLAS只会扩大我们对这一复杂主题的理解。 目标。 在这里，我们研究3I/ATLAS的光谱、彗星和旋转特性及其动力学背景。 方法。 我们从可见反射光谱确定了3I/ATLAS的光谱类型，并使用测光观测数据推导其活动水平和旋转特性。 观测数据是通过 OSIRIS相机光谱仪在10.4米大加那利望远镜和 两米双子望远镜上获得的。 我们使用N体模拟和Gaia DR3数据的统计分析来研究3I/ATLAS的起源及其银河系背景。 结果。 星际彗星3I/ATLAS的可见光谱与D型小行星的光谱一致，在 5000-9000 A范围内，其光谱斜率为14.6%/1000 A，这与奥陌陌相似，但比2I/Borisov和大多数太阳系彗星更红。 它有一个明显的彗发，其自转周期为16.79小时。 其银河速度的日心分量为（U，V，W）=（-51.233，-19.456，18.930）km/s，辐射点位于人马座。 从Gaia DR3中提取的3I/ATLAS运动学类比样本的分析表明，其母系统属于银河系薄盘，并包含一颗金属含量略低于太阳的恒星。 显示英文摘要

摘要： Context. Theories of the formation and evolution of small bodies in planetary systems predict that they may escape into interstellar space at any time. After having characterized just two such interlopers -1I/2017 U1 (Oumuamua) and 2I/Borisov more questions were raised than answered. Assessing the recently discovered interstellar comet 3I/ATLAS will only broaden our understanding of this complex topic. Aims. Here, we investigate the spectral, cometary, and rotational properties of 3I/ATLAS as well as its dynamical context. Methods. We identified the spectral type of 3I/ATLAS from the visible reflectance spectrum and used photometric observations to derive its level of activity and rotational properties. Observational data were obtained with the OSIRIS camera spectrograph at the 10.4 m Gran Telescopio Canarias and the Two-meter Twin Telescope. We used N-body simulations and statistical analyses of Gaia DR3 data to investigate the origin of 3I/ATLAS and its Galactic background. Results. Interstellar comet 3I/ATLAS has a visible spectrum consistent with that of a D-type asteroid, and has a spectral slope of 14.6%/1000 A in the 5000-9000 A range, which is similar to the one of Oumuamua but redder than that of 2I/Borisov and most solar system comets. It has a conspicuous coma and its rotation period is 16.79 h. The heliocentric components of its Galactic velocity were (U, V, W) = (-51.233, -19.456, 18.930) km/s with a radiant in Sagittarius. The analysis of a sample of kinematic analogs of 3I/ATLAS extracted from Gaia DR3 suggests that its parent system is part of the Galactic thin disk and includes a solar-like star with slightly sub-solar metallicity.