标题： 通过微透镜探测行星系统的全新通道：II. 重复事件 显示英文标题

标题： A New Channel for the Detection of Planetary Systems Through Microlensing: II. Repeating Events

摘要： 在姊妹篇中，我们开始系统地研究通过微透镜巡天探测宽轨道（$a > 1.5 R_E$）行星的任务。在这篇文章中，我们将继续这一工作，重点放在重复事件上。我们发现，如果所有行星系统都类似于我们的太阳系，那么现有观测策略的合理扩展将使我们每年能够探测到来自银晕方向的3到6个重复事件。实际上，如果多行星系统的普遍存在，未来的监测计划将会发现数千个恒星透镜事件，并且这些事件很可能包括在单个系统内不同行星作为透镜的情况，其光变曲线表现出多次重复。本文讨论了最大化探测所有宽轨道行星透镜事件的观测策略。我们还比较了宽轨道行星与共振透镜区域内的行星的可能探测率。我们发现，根据透镜源的行星质量和恒星半径值（这些值决定了有限源大小是否重要）以及观测者使用的测光灵敏度，宽轨道行星的探测可能是通过微透镜发现行星的主要途径。此外，我们还讨论了共振和宽轨道事件的结合如何帮助我们了解行星系统属性的分布（6.1节）。另外，通过确定短持续时间事件中由行星引起的比例，我们可以间接推导出所有短持续时间事件中可能由低质量MACHO引起的事件的比例（6.2节）。 显示英文摘要

摘要： In the companion paper we began the task of systematically studying the detection of planets in wide orbits ($a > 1.5 R_E$) via microlensing surveys. In this paper we continue, focusing on repeating events. We find that, if all planetary systems are similar to our own Solar System, reasonable extensions of the present observing strategies would allow us to detect 3-6 repeating events per year along the direction to the Bulge. Indeed, if planetary systems with multiple planets are common, then future monitoring programs which lead to the discovery of thousands of stellar-lens events will likely discover events in which several different planets within a single system serve as lenses, with light curves exhibiting multiple repetitions. In this paper we discuss observing strategies to maximize the discovery of all wide-orbit planet-lens events. We also compare the likely detection rates of planets in wide orbits to those of planets located in the zone for resonant lensing. We find that, depending on the values of the planet masses and stellar radii of the lensed sources (which determine whether or not finite source size is important), and also on the sensitivity of the photometry used by observers, the detection of planets in wide orbits may be the primary route to the discovery of planets via microlensing. We also discuss how the combination of resonant and wide-orbit events can help us to learn about the distribution of planetary system properties (S 6.1). In addition, by determining the fraction of short-duration events due to planets, we indirectly derive information about the fraction of all short-duration events that may be due to low-mass MACHOs (S 6.2).