Circumbinary planets from space-based transiting planet surveys

围绕恒星倍数运行的行星是一个受欢迎的科幻小说比喻，但是虽然在1995年确认了第一颗围绕太阳星星运行的系外行星，但第一颗环双星行星直到2011年才被宣布。但与已知的系外行星总数相比，已知的CBP数量仍然非常少。这限制了我们研究CBP系统的形成和演化的能力，CBP系统可能与单星行星系统的类似过程非常不同。已知的CBPs数量有限也限制了我们对基本参数分布的了解，目前的样本受到强烈的观测偏差的影响。大多数已知的过境CBPs是由NASA的开普勒使命发现的，但自从该使命不幸死亡以来，搜索工作一直由NASA的TESS卫星进行，最近有一些新的发现。在未来，欧空局的PLATO使命也有可能发现新的CBPs和扩大我们的样本，这些有趣的system.However，凌日环双星的检测需要更多的偶然的时机比是单星系统的情况。不仅行星的凌日与恒星食相比相形见绌，而且宿主双星和轨道行星之间的引力相互作用导致快速的轨道岁差。因此，几乎所有目前已知的过境点实际上都将在某个时候停止过境。然而，这个过程是周期性的，如果时间足够长，所有的一切最终都会再次过境。这也意味着以前没有过境的CBPs可能会出现在明显没有行星的食双星周围。这个项目将探索迷人的环双星行星世界，重点是使用天基天文台的数据来研究那些过境一颗或两颗主星的行星。该项目将首先在TESS对食双星的观测中寻找环双星候选行星。这些可能是具有许多可检测的凌日的短周期行星，或单凌日事件表明行星的轨道与其宿主双星不一致，甚至是通过日食时间变化检测到的非凌日CBP。在确定之后，将对候选CBPs进行建模，以对其特征进行初步估计并预测其未来演变，并将寻求进一步的观察，以确认候选CBPs是真实的并改善其特征。进一步的工作途径可能包括将搜索扩展到开普勒和K2的数据，或模拟CBP系统以评估其可探测性并限制行星存在于已知食双星系统中的可能性。还可以使用模拟数据探索优化CBP检测和分析的方法以及PLATO中CBP的潜在产量。

Planets orbiting stellar multiples are a popular science fiction trope, but while detection of the first exoplanet around a Sun-like star was confirmed in 1995, the first circumbinary planet was only announced in 2011.Since that announcement other circumbinary planets (or CBPs) have been found through transit detection, eclipse timing, and microlensing, but the number of known CBPs is still very small compared to the total number of known exoplanets. This limits our ability to investigate the formation and evolution of CBP systems, which may be very different from the similar processes for single-star planetary systems. The limited number of known CBPs also restricts our knowledge of the underlying parameter distributions, and the current sample is affected by strong observational biases.Most of the known transiting CBPs were discovered by NASA's Kepler mission, but since that mission's unfortunate demise the search has been taken up by NASA's TESS satellite, which has produced some recent new discoveries. In the future, ESA's PLATO mission is also likely to detect new CBPs and expand our sample of these interesting systems.However, detection of a transiting circumbinary requires more fortuitous timing than is the case for single-star systems. Not only are the planet's transits dwarfed by the stellar eclipses, but the gravitational interactions between the host binary stars and the orbiting planet lead to rapid orbital precession. Thus, nearly all of the currently known transiting CBPs will, in fact, cease transiting at some point. The process is periodic, however, and given long enough all will eventually transit once more. This also means that previously non-transiting CBPs may appear around apparently planetless eclipsing binaries.This project will explore the fascinating world of circumbinary planets, focusing on the use of data from space-based observatories to study those that transit one or both of their host stars. The project will start by searching for circumbinary planet candidates in TESS observations of eclipsing binaries. These could be short-period planets with many detectable transits, or single-transit events indicative of planets on orbits misaligned with their host binary, or even non-transiting CBPs detected through eclipse timing variations. Following their identification, candidate CBPs will be modelled to produce preliminary estimates of their characteristics and predict their future evolution, and further observations will be sought to confirm that the candidates are real and improve their characterisation. Further avenues of work could include extension of the search to data from Kepler and K2, or simulation of CBP systems to evaluate their detectability and constrain the likelihood of planets being present in known eclipsing binary systems. Methods for optimising detection and analysis of CBPs, and the potential yield of CBPs from PLATO, may also be explored using simulated data.