From the Centaurs to the Inner Oort Cloud: Exploring the Kuiper belt Connection

外太阳系的小天体是行星建造过程中遗留下来的物质，是太阳系历史的化石记录。这些行星体大致可以分为半人马星团、柯伊伯星带和内奥尔特云。柯伊伯带由海王星以外的轨道组成，大约位于30-250个Au之间。半人马是最近从柯伊伯带扩散出来的彗星前身。这些天体是海王星和木星之间相对短暂的混乱轨道上的短暂群体，这些轨道横跨一颗或多颗巨行星。另一方面，内奥尔特云由动态激发的和脱离海王星的轨道组成，半长轴大于~250 Au，很可能是被海王星外的一颗巨大的行星或经过的恒星散射到它们的轨道上。通过研究这些小行星的系综性质(形状、大小、组成、轨道等物理特性)，我们可以探索这些巨行星的早期动力学历史，探索太阳系原始行星盘的成分结构，并研究外太阳系随时间的演化。这些天体中的大多数太暗，无法用地面望远镜进行光谱分析，但通过测量不同光学和近红外滤光片的宽带颜色，我们获得了小行星表面组成的替代指标。通过测量小行星在一段时间内的亮度，我们可以估计形状和测量自转速度。通过深度光学成像，我们可以寻找与彗星类活动有关的微弱特征，并探索这些天体经历水、冰和其他挥发性物质放出气体的频率。该项目的主要目的是探索半人马、柯伊伯带和内奥尔特云的联系和演化历史。该项目将侧重于探索这些太阳系人口的两个主要途径。首先将利用1-8米望远镜和小行星对地撞击末次警报系统(ATLAS)的观测，研究KBO和半人马座彗星样本的光曲线、相位曲线和彗星活动历史。第二条途径将包括利用ATLAS调查来搜索遥远的内奥尔特云天体，以限制这一遥远天体群体的大小和明亮的星等分布。

The small bodies of the Outer Solar System are the material leftover from the construction of the planets and serve as a fossil record of the Solar System's history. These planetesimals can be broadly divided in the Centaurs, the Kuiper belt, and the Inner Oort cloud. The Kuiper belt consists of orbits beyond Neptune residing between approximately 30-250 au. Centaurs are cometary precursors that have recently diffused out of the Kuiper belt. These bodies are a transitory population on relatively short-lived chaotic orbits between Neptune and Jupiter that cross one or more of the giant-planets. The Inner Oort cloud on the other hand consists of dynamically excited and detached orbits from Neptune, with semimajor axes greater than ~ 250 au, likely scattered on to their orbits by a giant planet beyond Neptune or by a passing star. By studying the ensemble properties (shapes, sizes, compositions, orbits, and other physical characteristics) of these small icy planetesimals, we can probe the giant planets' early dynamical history, explore the compositional structure of the Solar System's primordial planetesimal disk, and study the evolution of the outer Solar System over time. The majority of these objects are too faint for spectroscopy with ground-based telescopes, but by measuring broad-band colors in different optical and near-infrared filters, we obtain a proxy for a planetesimal's surface composition. By measuring the brightness of a planetesimal over time, we can estimate shape and measure rotation rates. With deep optical imaging, we can look for faint features associated with comet-like activity and explore how often these objects experience outgassing of water ice and other volatile species.The main aim of this project is to explore the connection and evolutionary history of the Centaurs, Kuiper belt, and Inner Oort cloud. The project will focus on two main avenues for exploring these Solar System populations. The first will be through the study of light curves, phase curves, and the cometary activity histories of a sample of KBOs and Centaurs utilising observations from 1-8-m telescopes and the Asteroid Terrestrial-impact Last Alert System (ATLAS). The second avenue will consist of a search for distant inner Oort Cloud objects with the ATLAS survey in order to constrain the size and bright-end magnitude distribution of this distant population of bodies.