Studies of OH-Infrared Stars

目前天文学中引起强烈兴趣的一个课题是恒星的质量损失。质量损失几乎发生在恒星演化的所有阶段，尽管质量损失的速率变化很大。质量损失的一个更神秘的阶段发生在质量与太阳相似的恒星的红巨星阶段。这些恒星每年可能脱落10-3个太阳质量，从而产生行星状星云（以几公里/秒的速度膨胀的星周气体壳）。一些最明亮的红巨星周围的质量损失区域以强羟基脉泽发射为特征。首席研究员（PI）建议对这些区域进行理论和观测研究。研究的目的是更好地了解质量脱落过程；更详细地描述质量损失区的几何、动力学、热力学和磁性结构；并确定这种质量损失对星系化学演化的总体影响。

A subject of intense current interest in astronomy is mass loss from stars. Mass loss occurs during virtually all phases of stellar evolution, though the rate of mass loss varies considerably. One of the more enigmatic phases of mass loss occurs during the red giant phase of stars that have masses similar to that of the sun. These stars may shed up to 10-3 solar masses per year and thereby produce planetary nebulae (which are circumstellar gaseous shells that expand at speeds of a few km/sec). The mass loss regions surrounding some of the most luminous red giants are characterized by strong hydroxyl maser emission. The Principal Investigator (PI) proposes to investigate theoretically and observationally such regions. The objective of the research is to understand better the mass shedding process; to describe in greater detail the geometric, dynamic, thermodynamic, and magnetic structure of the mass loss regions; and to determine the collective influence of this mass loss on the chemical evolution of the galaxy.