Robotic Photometry of Magnetically Active Stars

该计划包括两项研究工作：对太阳型恒星的光度变化和磁活动的研究；以及对色球活动恒星中黑子的系统效应的研究。作为前一个项目的参与者，田纳西州立大学的一名天文学家、一名工程师和几名少数族裔学生将在加利福尼亚州帕萨迪纳附近的威尔逊山天文台建造并操作一台0.8米的机器人望远镜。目标是通过在更短的几年时间间隔内研究太阳型恒星的集合，深入了解太阳活动的短期和长期行为，特别是太阳的磁性和亮度在几十年到几个世纪的间隔内是如何变化的。通过研究其他具有不同质量和年龄的较低的主序恒星，可以进一步了解太阳整个主序生命周期中磁场活动和亮度的演变。对恒星的磁性和光度变化的详细研究将对理解太阳-恒星联系的物理原理以及评估太阳在平均全球温度变化模型中的潜在影响的不确定性和真正重要性产生深远的影响。到目前为止，他们对全球变暖的预测都是基于太阳不变的假设。通过将光谱与光度测量相结合，黑点的结构（即它们是由一个大的黑暗区域组成，还是像人们怀疑的那样由几个小的黑暗区域组成）将由另一组天文学家和该大学的少数民族学生确定。这一切之所以成为可能，是因为有关在色球活动的太阳型恒星上的黑点的信息正准备经历一场革命，这是自动望远镜大量观测的结果。这些数据将使许多单个斑点得以识别和研究，从它们的出现到消亡。作为该项目和相关项目的结果，科学家们将最终能够了解这些黑子与太阳黑子的特性比较，发现色球活跃的恒星对其表面10-30%被黑暗区域遮挡的反应，评估磁场对这些恒星亮度的影响（如果有的话）。并确定这些非常活跃的恒星是否真的有像太阳周期一样的活动周期。

The proposed program consists of two research efforts: An investigation of luminosity changes and magnetic activity in solar-type stars; and an investigation of the systematic effects of spots in chromospherically active stars. As participants in the former project, an astronomer and an engineer and several minority students at Tennessee State University will construct and operate a 0.8-m robotic telescope at Mount Wilson Observatory near Pasadena, California. The objective is to gain insight into the short and long-term behavior of solar activity, especially how the magnetism and luminosity of the Sun change over intervals of decades to centuries, by studying an ensemble of solar-type stars over a much shorter time interval of a few years. Additional insight into the evolution of magnetic activity and luminosity over the Sun's entire main-sequence lifetime may be gained by studying other lower main-sequence stars with a variety of masses and ages. This detailed study of magnetic and luminosity variations of stars will have far- reaching consequences for an understanding of the physical principles of the solar-stellar connection and for assessing the uncertainties and true importance of the Sun's potential influence in mean global temperature change models, which have so far based their predictions of global warming on the assumption of a constant Sun. By combining spectra with the photometry, the structure of spots (namely whether they consist of a single large dark area, as suspected, or several smaller dark areas close together) will be determined by another group of astronomers and minority students at the university. This is made possible by the fact that information about dark spots on chromospherically active solar-type stars is poised to undergo a revolution as the result of the extensive observations now piling up from automatic telescopes. These data will allow many individual spots to be identified and studied from their emergence to their demise. As a result of the project and related ones, scientists will finally be able to know just how properties of these spots compare with those of sunspots, to find how chromospherically active stars respond to having 10-30% of their surfaces blocked by dark areas, to assess just what effect-if any-magnetic faculae have on these stars' luminosities, and to determine whether such very active stars really do have cycles of activity like the solar cycle.