RUI: Search for Mode Switching in Semiregular Variable Stars

RUI（本科院校研究） 格兰特，卡德摩斯已经建立了设备和减少 需要通过光度计监测大约36个 半规则变星 他将监视这些星星， 三年后，按原计划。 卡德摩斯最近 观测到一颗变星星星在静止期改变了周期 状态 还将追求有趣的结果 光谱学上 许多恒星有规律地生长和收缩。 他们的观察 脉动提供了很多关于恒星内部的信息 和进化。 现在，人们对了解恒星的兴趣越来越大， 似乎不规则地搏动，也许偶尔改变 脉动模式 它们很可能提供新的质量 对恒星结构的深入了解 卡德摩斯建立了一个项目 测量选定的不规则变星的亮度 在足够长的时间内， 可以识别不规则性。 这笔赠款支持 监测计划和光谱的后续行动， 结果 学生们积极参与这项研究， 在本科生研究和 院校与大学生科研经历 程序.

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.