Planet Detection and Characterization from Transit Timing Variations

这个项目将改进研究系外行星系统中凌日光曲线变化的计算方法。从地球上看，当一颗行星从它的主星前面经过时，就被称为凌日。凌日表现为恒星亮度的周期性小减弱。在这个项目中，Nesvorny博士将探索两种类型的凌日光曲线变化（TLV），包括凌日光曲线中心时间的变化（TTV，或凌日时间变化）和凌日持续时间的变化（TDV，或凌日持续时间变化）。这样的研究原则上可以揭示系统中其他行星对观测到的凌日行星造成的扰动。TLV程序是一种很有前途的探测行星的方法，这种方法不容易被任何其他行星探测技术发现，包括类地行星。Nesvorny博士将开发一种新的行星探测方法，该方法具有显著推进系外行星探测的能力。新方法依赖于监测已知凌日系外行星的tlv。通过tlv与凌日行星的引力相互作用，可以推断出其他行星。他将使用新方法：(i)确定tlv对行星的可探测极限；（ii）估计行星系统独特特性所需的测量精度；(3)确定凌日观测的最佳观测策略。这里开发的方法可用于通过TLV信号搜索行星，估计此类探测所需的测量精度，并确定最佳观测策略。因此，拟议的工作将增加诸如CoRoT和开普勒等卫星项目的科学成果。Nesvorny博士还计划与丹佛自然科学博物馆的工作人员合作，向公众发布这项研究的结果。

This project will improve computational methods for studying variations in transit lightcurves in exoplanet systems. A planet is said to transit its host star when it passes in front of the star as viewed from the Earth. Transits manifest themselves as small, periodic reductions in the brightness of the star. In this project, Dr. Nesvorny will explore two types of transit lightcurve variations (TLV), including variations in the central time of the transit lightcurve (TTV, or transit time variation), and in the duration of the transit (TDV, or transit duration variation). Such studies can in principle reveal perturbations to the observed transiting planet caused by other planets in the system. TLV programs are a promising way of detecting planets not easily seen by any other planet-detection techniques, including Earth-like planets. Dr. Nesvorny will develop a new planet-detection method that has a capability of significantly advancing exoplanet detection. The new method relies on monitoring TLVs of known transiting exoplanets. Additional planets can be inferred from TLVs by their gravitational interactions with the transiting planet. He will use the new method to: (i) identify the detectability limits of planets from TLVs; (ii) estimate the measurement precision required for unique characterization of planetary systems; and (iii) determine the optimal observing strategy for transit observations. The method developed here can be used to search for planets through TLV signals, estimate the measurement accuracies needed for such detections, and to determine the best observational strategies. The proposed work will thus increase the scientific outcome from satellite projects such as CoRoT and Kepler. Dr. Nesvorny also plans collaborations with staff at Denver Museum of Nature and Science to distribute the results from this study to the public.