Development of a Dedicated Spectrograph for Robotically Measuring Chromospheric Emission of Stars like the Sun

开发用于自动测量太阳等恒星色层发射的专用光谱仪

• 批准号: 0618404
• 负责人: Joel Eaton
• 金额: $ 22.1万
• 依托单位: Tennessee State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0618404&HistoricalAwards=false
• 关键词: Development; Dedicated; Spectrograph; Robotically; Measuring

AST-0618404Joel EatonTennessee State UniversityTennessee State University will build a dedicated spectrograph for robotically tracking changes in the chromospheric activity of stars like the Sun. The Sun has a zone in its upper atmosphere, called the chromosphere, which is formed and heated by magnetic fields. The amount of emission of the hot gases in the chromosphere tells us how much magnetic field the Sun is generating in its internal dynamo. The magnetic field, and the resulting emission, varies on an 11-year cycle, but longer cycles have been documented. Space-based observations have shown that the Sun's total brightness changes somewhat over this 11-year cycle; historical data suggest it can change a great deal more over the longer cycle. The observations made with the new spectrograph will document magnetic cycles in about 300 stars chosen to approximate conditions of the Sun in the past, present, and near future. In combination with precise photometry already being collected on TSU telescopes for these same stars, the new data will define the way magnetic activity changes the luminosity of Sun-like stars and predict how much the Sun itself should vary. The combined spectroscopic and photometric results will ultimately determine whether old stars like the Sun are cyclically variable and just what kind of magnetic cycles these old dwarf stars typically have, hence how typical is the Sun itself. They will determine how prevalent times of very low magnetic activity, such as the Sun's Maunder minimum of the 17th century, are in these stars. These observations will further define how the history of solar magnetism may have affected development of life on the Earth.The spectrograph is designed with few moving parts and to be integrated into an existing 2-meter, automatic telescope. The spectrograph will measure chromospheric emission of ionized calcium in the near ultraviolet spectra of stars to about V=8 magnitude. Observing robotically, without human telescope operators, will make it possible to obtain more observations per star and to maintain the program more easily into the future. It should be possible to follow these stars for decades. These data from TSU will ultimately give us a deep understanding of the level and timescales of changes in the Sun's output of total energy and magnetic field. This is crucially important for understanding just how much the Sun affects our climate and thereby our economy. The development of this instrument at TSU ,a small, historically black university, will advance ethnic diversity in science and engineering by involving African-American students in development and use of state-of-the-art instrumentation.

田纳西州立大学州立大学将建造一台专用的光谱仪，用于自动跟踪太阳等恒星色球活动的变化。 太阳的上层大气中有一个区域，称为色球层，由磁场形成和加热。 色球层中热气体的排放量告诉我们太阳在其内部发电机中产生了多少磁场。磁场和由此产生的辐射以11年为一个周期，但更长的周期已经被记录在案。 太空观测表明，太阳的总亮度在这11年的周期内会有所变化;历史数据表明，在更长的周期内，它会发生更大的变化。使用新光谱仪进行的观测将记录大约300颗恒星的磁周期，这些恒星被选择来近似太阳在过去，现在和不久的将来的条件。 结合大津望远镜已经收集的这些恒星的精确测光，新数据将定义磁场活动改变类太阳恒星光度的方式，并预测太阳本身应该变化多少。 光谱学和光度学的综合结果将最终确定像太阳这样的老恒星是否是周期性变化的，以及这些老矮星通常具有什么样的磁周期，从而确定太阳本身的典型性。 他们将确定非常低的磁场活动，如太阳的蒙德最低的世纪，是在这些恒星的普遍时间。 这些观测结果将进一步确定太阳磁场的历史可能如何影响地球上生命的发展。摄谱仪的设计几乎没有移动部件，并将集成到现有的2米自动望远镜中。 摄谱仪将测量恒星近紫外光谱中电离钙的色球发射，大约V=8等。 在没有人类望远镜操作员的情况下进行机器人观测，将有可能获得每颗星星更多的观测结果，并更容易在未来维持该计划。 应该可以跟踪这些恒星几十年。 这些来自大津的数据最终将使我们深入了解太阳总能量和磁场输出变化的水平和时间尺度。 这对于了解太阳对我们的气候以及我们的经济有多大影响至关重要。 大津是一所历史悠久的小型黑人大学，该仪器的开发将通过让非洲裔美国学生参与开发和使用最先进的仪器来促进科学和工程领域的种族多样性。