RUI: Search for Mode Switching in Semiregular Variable Stars

在先前的本科机构研究（RUI）资助下，卡德摩斯已经建立了设备和减少程序，需要对大约36颗半规则变星进行光度监测。他将按原计划在今后三年内监测这些星星。卡德摩斯最近观测到一颗变星在静止状态下改变了周期。有趣的结果也将追求光谱。许多恒星有规律地生长和收缩。对它们脉动的观测提供了许多关于恒星内部和演化的信息。现在，人们对了解那些似乎不规则地脉动，也许偶尔会改变脉动模式的恒星越来越感兴趣。它们很可能为恒星结构提供定性的新见解。卡德摩斯建立了一个计划，在足够长的时间内测量选定的不规则变星的亮度，以便确定不规则变星的原因。这笔拨款支持监测计划和有趣结果的光谱跟踪。学生密切参与这项研究，并在本科院校研究和本科生研究经验项目下提供支持。

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.