The HI 21-cm Line as a Probe of Stellar Mass Loss and Evolution

这是一个观测项目，绘制出附近渐近巨星分支（AGB）和造父变星的星周包层中氢原子的21厘米发射线，以便更好地了解恒星质量损失和恒星演化的后期阶段。PI将使用来自甚大阵列（VLA）的数据来更好地估计星周包层的总质量，范围和化学性质，对恒星演化后期质量损失的持续时间和几何形状的新见解，以及对造父变星不稳定带发生质量损失的新限制，以及更好地了解演化恒星如何与周围星际介质相互作用。更广泛的影响包括通过本科生研究经验计划培训本科生，在所谓的广播明星上制作教育播客，公开提供数据和数据产品，并将研究纳入公共讲座。

This is an observational project to map out the 21-cm emission line of atomic hydrogen in the circumstellar envelopes of nearby Asymptotic Giant Branch (AGB) and Cepheid variable stars in order to better understand stellar mass loss and late stages of stellar evolution. The PI will use data from the Very Large Array (VLA) to provide better estimates of the total mass, extent and chemistry of circumstellar envelopes, new insights into the duration and geometry of mass-loss during the late stages of stellar evolution and new constraints on the occurrence of mass loss on the Cepheid instability strip, as well as better understanding of how evolved stars interact with the surrounding interstellar medium. Broader impacts include training undergraduate students through the Research Experiences for Undergraduates program, producing an educational podcast on so-called radio stars, making data and data products publicly available, and incorporating research into public lectures.