Asteroid spin and surface properties

大多数小行星都有非球形的形状，导致亮度随时间的变化（光变曲线），从中可以确定它们的旋转周期。相位函数描述了小行星亮度的变化，作为太阳相位角（地球和太阳在小行星上对向的方向之间的角度）的函数。相位函数的形式在不同光谱类别的小行星之间各不相同，并包含关于其表面物理性质的信息。在极少数情况下，亮度变化也可能是由于整个表面的日冕变化，月食/掩星和撞击，挥发性升华或自旋的质量喷射造成的。为了检测这种可能导致亮度或颜色变化小到百分之几的影响，需要很好地理解潜在的旋转光变曲线和相位校正。这一项目将把正在进行的观测方案与小行星的特性联系起来，同时开发利用我国望远镜观测移动物体的新能力。它将利用开放科学天文台位于加那利群岛特内里费岛泰德天文台（OT）的特内里费岛设施PIRATE和COAST（见pirate.open.ac.uk，telescope.org），这是北方半球最好的天文台之一。观测控制系统需要增加一个跟踪在太阳轨道上移动的物体的模块。这项任务将与观测站控制软件的开发人员合作完成。数据简化管道还需要添加一个选项来处理移动对象，并对轨迹进行测光。具体而言，学生将在以下任务中发挥主导作用：（一）开发并协助实施望远镜支架跟踪太阳系物体的软件算法（二）开发自动监测移动物体的优化协议（三）确定在近距离飞越期间观察明亮近地小行星的机会，这使得大相位角覆盖范围成为可能。(iv)对小行星样本进行长期多波段光度监测

Most asteroids have a non-spherical shape, resulting in variations in brightness with time (light curves) from which their spin period can be determined. The phase function describes the change in brightness of an asteroid as a function of solar phase angle (the angle between the directions of the Earth and Sun subtended at the asteroid). The form of the phase function varies between and among different spectral classes of asteroids, and contains information on the physical nature of their surfaces. In rare cases brightness changes can also result from albedo variations across the surface, eclipses/occultations of moons and mass ejection from impacts, volatile sublimation or spin-up. In order to detect such effects, which may cause changes in brightness or colour of as small as a few per cent, the underlying rotational light curve and phase corrections need to be well understood. This project will link ongoing observational programmes to characterise asteroid properties with development of new capabilities for moving object observations with our telescopes. It will make use of the OpenScience Observatories' Tenerife facilities PIRATE and COAST (see pirate.open.ac.uk, telescope.org), located at the Observatorio del Teide (OT), Tenerife, Canary Islands, one of the best northern hemisphere observatory sites. The observatory control system requires the addition of a module to track objects moving on solar orbits. This task will be completed in collaboration with the developers of the observatory control software. The data reduction pipeline also needs the addition of an option to deal with moving objects, and to conduct photometry of tracklets. Specifically, the student will take a leading role in the following tasks: (i) Develop and assist in implementing a software algorithm for the telescope mount to track solar system objects (ii) Develop optimized protocols for the automated monitoring of moving objects (iii) Identify opportunities to observe bright near-Earth asteroids during close flybys, which enable large phase angle coverage. (iv) Conduct long-term multi-band photometric monitoring of a sample of asteroids (v) Refine a processing-pipeline for the data stream from the OT to OU, to cater for moving objects