RUI: Search for Mode Switching in Semiregular Variable Stars

RUI：搜索半规则变星中的模式切换

• 批准号: 8718533
• 负责人: Robert Cadmus
• 金额: $ 6.03万
• 依托单位: Grinnell College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8718533&HistoricalAwards=false
• 关键词: RUI; Search; Mode; Switching; Semiregular

Under a previous RUI (Research in Undergraduate Institutions) grant, Cadmus has established the equipment and reduction procedures needed to monitor photometrically about three dozen semiregular variable stars. He shall monitor those stars during the next three years, as originally planned. Cadmus recently observed one variable star to change its period during a quiescent state. Interesting results will also be pursued spectroscopically. Many stars grow and shrink regularly. The observation of their pulsations has provided much information about stellar interiors and evolution. Now interest grows in understanding stars that appear to pulsate irregularly, perhaps occasionally changing pulsation modes. They are likely to provide qualitatively new insights into stellar structure. Cadmus has established a program to measure the brightness of selected irregularly variable stars over long enough time periods so that the causes of the irregularity may be identified. This grant supports the monitoring program and the spectroscopic follow-up of interesting results. Students are closely involved in this research, and support is provided under both the Research in Undergraduate Institutions and the Research Experiences for Undergraduates programs.

根据之前的RUI(本科生研究机构)拨款，卡德默斯已经建立了对大约30多颗半规则变星进行光度测量所需的设备和还原程序。他将按原计划在未来三年内监测这些恒星。卡德摩斯最近观测到一颗变星在静止状态下改变其周期。有趣的结果也将通过光谱分析来追求。许多恒星有规律地大小不一。对它们脉动的观察提供了许多关于恒星内部和演化的信息。现在，人们对了解看起来不规则脉动的恒星越来越感兴趣，也许偶尔会改变脉动模式。它们很可能为恒星结构提供质的新见解。卡德摩斯已经建立了一个计划，在足够长的时间内测量选定的不规则变化恒星的亮度，以便确定不规则的原因。这笔赠款支持监测计划和对有趣结果的光谱跟踪。学生们密切参与这项研究，并在本科院校研究和本科生研究经验计划下提供支持。