Rotation and Oxygen Abundances of Horizontal Branch Stars

彼得森博士将探索恒星内部旋转和氧丰度对恒星演化过程中核心燃烧阶段（水平分支阶段）特性的影响。虽然总体金属丰度是控制恒星在水平分支上位置的主要因素，但很明显，还有一个“第二个”参数也会影响它的位置。对于第二个参数，人们提出了许多物理变量——年龄、氦、氧和碳丰度、旋转和其他控制质量损失量的参数——但没有一个单一的“第二个”参数被清楚地确定。彼得森博士建议在更大的恒星和球状星团样本中继续研究氧丰度和自转的影响，以绘制这些参数的影响图。新的观测结果和对现有观测结果的分析将描绘出恒星旋转和氧丰度的趋势，这些趋势涉及广泛的星团金属丰度、HB形态和浓度，并在选定的星团中提供更广泛的样本。* * *

Peterson, Ruth AST 96-18502 Dr. Peterson will explore the influence stellar internal rotation and oxygen abundance have on a star's properties during the core-He burning phase of evolution (the Horizontal Branch phase). Although overall metallicity is a primary factor controlling the location of a star on the Horizontal Branch, it is clear there is a 'second' parameter that also influences its position. Many physical variables have been proposed for the second parameter - age, helium, oxygen, and carbon abundances, rotation, and other parameters that control the amount of mass loss - but no single 'second' parameter has been clearly identified. Dr. Peterson proposes to continue investigations into the effects of oxygen abundance and rotation in a larger sample of stars and globular clusters to map the influence of these parameters. New observations and the analysis of observations in hand will delineate trends in stellar rotation and oxygen abundances across a wide range of cluster metallicity, HB morphology and concentration, as well as provide more extensive samples within selected clusters. ***