Asteroid spin and surface properties

大多数小行星都是非球形的，这导致它们的亮度随时间的变化（光曲线），由此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是太阳相位角的函数（地球和太阳的方向在小行星上的夹角）。相函数的形式在不同光谱类别的小行星之间是不同的，并且包含了它们表面物理性质的信息。在极少数情况下，亮度的变化也可能是由于表面反照率的变化、月球的日食/掩星、撞击产生的物质喷射、挥发性升华或自旋上升造成的。为了检测这种可能导致亮度或颜色变化的影响，需要很好地了解潜在的旋转光曲线和相位修正。这个项目将把正在进行的小行星特性观测项目与我们的望远镜观测移动物体的新能力的发展联系起来。它将利用开放科学天文台的特内里费岛设施PIRATE和COAST（见PIRATE .open.ac）。位于加那利群岛特内里费岛的泰德天文台（OT），这是北半球最好的天文台之一。天文台控制系统需要增加一个模块来跟踪在太阳轨道上移动的物体。这项任务将与天文台控制软件的开发人员合作完成。数据缩减管道还需要增加一个选项来处理移动的物体，并对轨道进行光度测定。具体而言，该学生将在以下任务中发挥主导作用：(i)开发并协助实施望远镜架跟踪太阳系物体的软件算法；（ii）开发自动监测移动物体的优化协议；（iii）在近距离飞掠期间确定观测明亮近地小行星的机会，这可以实现大相位角覆盖。（iv）对小行星样本进行长期多波段光度监测(v)完善从外象仪到外象仪的数据流处理管道，以满足移动物体的需要

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