HRT activity monitoring of solar-like stars: The Ca II Infrared triplet

Ca II三线是一个研究较少的恒星活动指示器，它位于近红外区，而Ca II HK线几十年来一直被用作恒星色球活动指示器。 由于仪器的问题，这些线的同时数据集很少，然而，与中阶梯光谱仪的可用性，覆盖了广泛的光谱范围，它是直接获得同时覆盖的Ca II H&K和IRT线。同时采取的数据集需要回答的问题，如果钙II IRT为基础的活动指标可以发挥同样的作用，那些基于钙II H&K线。这些谱线是由相同的离子产生的，然而，它们是在不同的大气层中产生的，因此不需要具有相同的诊断能力。无论是在CARMENES上，一个对M星周围行星的光谱调查，还是在GAIA上，只有Ca II IRT将被覆盖作为活动诊断，并且已经出于这些原因，有必要对冷星进行活动研究，同时覆盖两条Ca II线，以便能够将即将到来的Ca II IRT数据与Ca II H&K线上的大量文献联系起来。在拟议的项目中，我们希望同时观察和监测Ca II H&K和Ca II IRT线在更大的恒星样本。所需的光谱时间序列可以通过机器人望远镜经济地获得。汉堡机器人望远镜可以生成所需数据，并可用于拟议项目。

A relatively little study stellar activity indicator is the Ca II triplet, Iocated in the near infrared, while the Ca II HK lines haven been used for decades as stellar chromospheric activity indicators. Because of instrumental problems few simultaneous data sets of these lines are available, however, with the availability of echelle spectrographs, covering a wide spectral range, it is straightforward to obtain simultaneous coverage of the Ca II H&K and IRT lines. Such simultaneously taken data sets are required to answer the question if Ca II IRT based activity indicators can play the same role as those based on the Ca II H&K lines. These lines are produced by the same ion, however, they are generated in different atmospheric layers and need thus not have the same diagnostic power. Both on CARMENES, a spectroscopic survey for planets around M stars, as well as on GAIA, only the Ca II IRT will be covered as an activity diagnostics, and already for these reasons it is necessary to carry out an activity study of cool stars, which covers both Ca II lines simultaneously, to be able to relate the upcoming Ca II IRT data to the huge body of literature available on the Ca II H&K lines. In the context of the proposed project we want to simultaneously observe and monitor the Ca II H&K and Ca II IRT lines in a larger sample of stars. The required spectral time series can be obtained economically through robotic telescopes. The Hamburg Robotic Telescope can generate the required data and is available to the proposed project.