Asteroid Lightcurve Observations and Analysis

华纳博士和他的团队继续他们现有的计划，每年制作大约100条小行星光曲线。光曲线观测测量小行星光线随时间的变化，是可以用普通仪器(不到0.5米)望远镜和高端商业CCD相机完成的富有成效的研究项目之一。较小的望远镜可以获得光曲线，用于对小到大约2-5公里的物体进行建模，直到最大的小行星。光曲线观测是在几天到几周内获得的，根据这些数据，可以确定小行星的自转速度、基于多色光度测量的分类、绝对星等(因此是其大致大小)、表面光散射特性，有时还可以初步指示其形状和自旋轴方向。这些特征限制了有关太阳系内小行星发展和演化的理论。这些结果有助于理解小行星对太阳光进行热重辐射的两个过程：第一，Yarkovsky效应，它改变了物体轨道的大小；第二，YORP效应(Yarkovsky-O‘Keefe-Radzievskii-Paddack)，据信该效应负责在小行星群或小行星家族内对齐自旋轴。YORP效应被认为是形成小型双星小行星的主要机制，它使母星自转到一个点，在那里它失去质量，成为卫星。。该项目还发现了十几颗双星小行星，接下来可能还会有更多的发现。新的光曲线数据被用来发展关于双星形成、自旋轴取向和轨道迁移的想法，以及更清楚地定义雅可夫斯基和YORP效应在小行星演化中的作用。华纳和他的团队通过定期在小行星公报上发表列出潜在目标的季度文章；Call(合作小行星光曲线链接)网站，列出目标并提供帮助协调观测工作的‘预订’系统；以及维护小行星光曲线数据库(LCDB)，与其他光曲线和双星搜索项目协调工作。该数据库提供所有光线曲线结果的最新结果，并经常被其他研究人员使用。这个项目吸引了世界各地教育机构的大量高中生和本科生和教职员工，以及普通公众(后院天文学家)参与天文研究。

Dr. Warner and his team continue their existing program to produce about 100 asteroid lightcurves per year. Lightcurve observations measure the changes in light from an asteroid over time, and are among the productive research projects that can be done with modest instrument (less than 0.5-m) telescopes and high-end commercial CCD cameras. Smaller telescopes can obtain lightcurves for modeling of objects as small as about 2-5 km and up to the largest asteroids. Lightcurve observations are obtained in a few days to weeks, and from these data it is possible to determine the rotation rate of an asteroid, its taxonomic class based on multi-color photometry, absolute magnitude (and thus its approximate size), surface light scattering properties, and sometimes an initial indication of its shape and the spin axis orientation. These characteristics provide constraints on theories regarding the development and evolution of the asteroids within our Solar System. The results help to understand two processes involving the thermal re-radiation of sunlight by asteroids: First, the Yarkovsky effect, which changes the size of an object's orbit and, second, the YORP effect (Yarkovsky-O'Keefe-Radzievskii-Paddack), which is believed to be responsible for aligning the spin axes within asteroid groups or families. The YORP effect is thought to be the primary mechanism for forming small binary asteroids by causing a parent asteroid to spin up to a point where it sheds mass that becomes a satellite. . The project has also lead to the discovery of a dozen binary asteroids, and more discoveries might follow. The new lightcurve data are used to develop ideas on binary formation, spin axis orientation, and orbital migration, along with more clearly defining the role of the Yarkovsky and YORP effects on asteroid evolution.Dr. Warner and his team coordinate their efforts with other lightcurve and binary search programs through regularly published quarterly articles in the Minor Planet Bulletin that lists potential targets; the CALL (Collaborative Asteroid Lightcurve Link) web site that lists targets and provides a 'reservation' system to help coordinate observing efforts; and through maintaining the asteroid Lightcurve Database (LCDB). This database gives up-to-date results of all lightcurve results and is frequently used by other researchers. This project engages a large number of high school and undergraduate students and faculty at educational institutions around the world, as well as the general public ('backyard astronomers') in astronomical research.