Two Suns in the sky: the TEST telescope on the quest for planets around binary stars

陶腾堡系外行星搜索望远镜是一个30厘米的机器人施密特望远镜，用于寻找太阳系外行星。它监测预先选定的天体场，以探测太阳系外行星。作为一个机器人望远镜，它参与矮网络是必不可少的。这个网络由20个主要是欧洲的望远镜组成，寻找围绕一种特殊类型的双星，即所谓的食双星的行星。这些双星以一种方式相互旋转，使得一颗星星在另一颗恒星前面经过，从而遮蔽了它的光线。这导致了系统总亮度的实质性和严格的周期性变暗，即所谓的日食。因此，我们可以通过观测双星的亮度来得出结论，即使这两个分量由于距离太远而无法分辨。如果一颗行星在围绕这颗双星的轨道上，严格来说，行星和双星都围绕着一个共同的质量中心运动。因此，双星的距离周期性地变化，因此双星的光旅行时间也是如此。这就导致了食分时刻的变化，并且双星越亮，望远镜越大，测量的精度就越高。TEST望远镜将被优化，以观测这种食分双星。几十个双星的观测计划将自动组织起来，以便有效地观测到许多恒星的许多日食。为了提高矮星系网络的成功率，需要识别和监测最好的双星目标。作为Dwarf网络中最小的望远镜之一，TEST非常适合在数百个候选者中找到最有希望的目标，而较大的望远镜则用于雄心勃勃地监测最佳候选者的日食时间。此外，测试将通过测量选定的明亮物体的日食时间来促进矮星活动。最后，该项目将提供资源来分析矮人项目收集的大量日食时间测量结果。该项目确保未来几年先进望远镜的运行和开发，同时为雄心勃勃的开创性科学做出贡献。自动化观测的发展将推进对双星周围行星的搜索。

The Tautenburg Exoplanet Search Telescope is a robotic 30cm Schmidt telescope to find extra-solar planets. It monitors celestial fields selected beforehand to detect extrasolar planets. Being a robotic telescope, its participation in the Dwarf network is essential. This network consists of 20 mostly European telescopes and looks for planets around a particular class of binary stars, the so-called eclipsing binaries.These binaries revolve around each other in a way so that one star transits in front of the other and thus shades its light. This results in a substantial and strictly periodical dimming of the total brightness of the system, the so-called eclipses. Therefore, one can conclude on the binary nature of the system by monitoring the brightness, even though the two components cannot be resolved due to the large distance.If a planet is in an orbit around this binary, both the planet and the binary move around a common centre of mass, strictly speaking. Therefore, the distance of the binary varies periodically and thus the light travel time of the binary, too. This results in a measurable variation of the exact eclipse times and can be measured more precisely the brighter the binary and the larger the telescope.The TEST telescope will be optimised for the observation of such eclipsing binaries. The observing schedule for tens of binaries will be organised automatically in a way so that many eclipses of many stars are observed efficiently.In order to increase the success of the Dwarf network, the best binary targets need to be identified and monitored. Being one of the smallest telescopes in the Dwarf network, the TEST is perfectly suited to find the most promising targets among hundreds of candidates while the larger telescope are used for the ambitious monitoring of the eclipse times of the best candidates. Moreover, the TEST will contribute to the Dwarf campaign by measuring eclipse times for selected bright objects. Finally, the project will provide resources to analyse the large amount of eclipse time measurements collected by the Dwarf project.The project ensures the operation and development of an advanced telescope over the next years and at the same time contributes to ambitious and seminal science. The development of automated observations will advance the search for planets around binary stars.