Stellar and Solar Magnetic Activity Cycles

这项工作扩展了洛厄尔天文台太阳-恒星摄谱仪（SSS）项目，该项目自1994年以来一直在运行。SSS是一种双阶梯光谱仪，用于对太阳和类太阳恒星进行独特的、长期的天气观测。在这个项目中，首席研究员（PI）将在太阳周期最小的23/24期间获得Ca II H和K太阳发射线的观测结果，并对大约40颗“太阳模拟”恒星进行类似的测量。这些钙II发射线作为太阳和恒星色球活动的代用物，可以用来研究周期行为。太阳光度的长期趋势最好在周期极小值时确定，这对于理解太阳光度的长期变化是至关重要的。这些太阳观测将使PI的团队能够对连续的太阳极小期的辐射进行详细的比较，以便与正在进行的太阳总辐照度（TSI）测量进行比较。对于恒星，这样的Ca II观测提供了恒星活动周期、旋转调制和微分旋转的直接观测证据。PI的团队已经确定了一组大约40颗“太阳模拟”恒星，这些恒星可能为恒星活动和亮度的行为提供关键线索。研究这些恒星可以让我们了解太阳的过去和未来。通过更好地描述太阳光度的演变和太阳最近的类似恒星的演变，这些观测可能提供关于太阳长期活动和光度变化的天体物理学见解，也可能有助于确定太阳对地球气候变化的可能影响程度。PI团队将对北亚利桑那大学的学生进行太阳和恒星观测以及天文数据分析方面的培训。该项目还将包括一名高中生对活跃双星的补充观测，这是他所在学区实施的加速研究计划的一部分。PI将继续在网上传播他的研究结果，以供公众广泛查阅、教育和参与。PI的团队将通过在亚利桑那州和西南地区展示他们的成果，继续积极参与公共宣传。

This effort extends the Lowell Observatory Solar-Stellar Spectrograph (SSS) project, which has operated continuously since 1994. The SSS is a dual echelle spectrograph used for unique, long-term, synoptic observations of the Sun and Sun-like stars. In this project, the Principal Investigator (PI) will obtain observations of the Ca II H and K solar emission lines during the minimum of solar cycle 23/24, as well as make similar measurements for about 40 'solar analog' stars. These Ca II emission lines serve as proxies for solar and stellar chromospheric activity and can be used to study cyclical behavior. Secular trends in solar luminosity are best identified at cycle minima, and are critical for understanding long-term solar luminosity variations. These solar observations will allow the PI's team to make detailed comparison of emissions at successive solar minima, for comparisons with ongoing total solar irradiance (TSI) measurements. For stars, such Ca II observations have provided direct observational evidence for stellar activity cycles, rotational modulation, and differential rotation. The PI's team has identified a set of about 40 'solar analog' stars that may provide critical clues regarding the behavior of stellar activity and luminosity. Studying these stars could provide insight into the Sun's past and future. By better characterizing the evolution of solar luminosity and that of the Sun's nearest stellar analogs, these observations may provide astrophysical insight into long-term solar activity and luminosity variations, and may also be useful for determining the likely level of solar influences on terrestrial climate change.The PI's team will train Northern Arizona University students in solar and stellar observing and astronomical data analysis. The project will also involve a high school student in complementary observations of active binary stars as part of an accelerated research program operated by his school district. The PI will continue to disseminate his results online for broad public access, education, and participation. The PI's team will remain active in public outreach by offering presentations of their results throughout Arizona and the Southwest.