The Ages of Nearby A-Type Stars

许多被研究得最好的行星系统都围绕着a型恒星运行，这是一种比太阳稍大的恒星。这个项目将使用佐治亚州立大学的高角分辨率天文干涉仪阵列中心（CHARA）来确定这些恒星的基本特性（例如，大小和表面温度），以及其他一些东西，将使更准确地估计它们的年龄。准确的年龄对于确定行星系统如何随时间变化至关重要。该项目将培养一名初级天文学家（博士后研究员）和两名本科生在一个备受瞩目的科学研究领域。项目参与者还将参加乔治亚州立大学艰苦劳动溪天文台的公共宣传活动。该团队将使用CHARA干涉仪阵列来调查附近的60颗a型恒星。他们将精确测量快速旋转恒星的扁圆形状，并模拟重力变暗的影响。这些测量将提供与进化模型更精确的比较，从中可以推断质量和年龄。这些结果可能会推动新的科学进步，包括对解释恒星快速旋转的进化模型的测试，对一些a型恒星如何以及为什么具有化学特殊性的理论的限制，其中一些恒星所拥有的碎片盘和/或行星系统的进化阶段的时间印记，以及纠正更遥远的质量和年龄估计偏差的经验关系，因此空间上无法解决，快速旋转的a型恒星。

Many of the best studied planetary systems orbit nearby A-Type stars, which are stars that are slightly more massive than the Sun. This project will use Georgia State University's Center for High Angular Resolution Astronomy interferometer array (CHARA) to determine the fundamental properties of these stars (for example, sizes and surface temperatures) that, among other things, will enable much more accurate estimates of their age. Accurate ages are critical for determining how planetary systems change with time. This program will train a junior astronomer (a postdoctoral researcher) and two undergraduate students in a high profile area of scientific research. Project participants will also participate in public outreach activities at Georgia State University's Hard Labor Creek Observatory. The team will use the CHARA interferometer array to survey 60 nearby A-Type stars. They will precisely measure the oblate shapes of rapidly rotating stars and model the effect of gravity darkening. These measurements will provide more accurate comparisons with evolutionary models, from which masses and ages can be inferred. The results could enable new scientific advances, including tests of evolutionary models that account for rapid stellar rotation, constraints on theories for how and why some A-Type stars are chemically peculiar, a temporal stamp for the evolutionary stage of the debris disks and/or planetary systems that some of these stars harbor, and empirical relations for correcting the biases in mass and age estimates of more distant, and thus spatially unresolved, rapidly rotating A-Type Stars.