利用 VERITAS 切伦科夫望远镜对恒星角直径的直接测量
太阳与恒星天体物理
2019-04-15 v1 高能天体物理现象
天体物理仪器与方法
摘要
恒星的角尺度是决定其基本性质的关键因素。恒星角直径的直接测量十分困难：在星际距离上，恒星通常太小，无法由任何单个成像望远镜分辨。这一根本限制可通过研究小行星掩星时投下阴影中的衍射图样来克服，但前提是测光不确定度小于大气闪烁所引入的噪声。用于粒子天体物理观测的大气切伦科夫望远镜，由于镜面光学质量一般，通常未被用于光学天文。然而，其大镜面面积使其非常适合于此类高时间分辨率精密测光测量。本文报道由 VERITAS 切伦科夫望远镜以毫秒采样观测到的两次恒星掩星事件，由此我们能够在 毫角秒尺度上对掩食恒星的角直径提供直接测量。这是光学测量此前从未达到的分辨率，并比等效的月掩星方法提高了一个数量级。我们将所得恒星半径与由温度和亮度测量经验推导的估计进行比较，证实后者对于恒星分类模糊的恒星可能存在偏差。
引用
@article{arxiv.1904.06324,
title = {Direct measurement of stellar angular diameters by the VERITAS Cherenkov Telescopes},
author = {W. Benbow and R. Bird and A. Brill and R. Brose and A. J. Chromey and M. K. Daniel and Q. Feng and J. P. Finley and L. Fortson and A. Furniss and G. H. Gillanders and C. Giuri and O. Gueta and D. Hanna and J. Halpern and T. Hassan and J. Holder and G. Hughes and T. B. Humensky and A. M. Joyce and P. Kaaret and P. Kar and N. Kelley-Hoskins and M. Kertzman and D. Kieda and M. Krause and M. J. Lang and T. T. Y. Lin and G. Maier and N. Matthews and P. Moriarty and R. Mukherjee and D. Nieto and M. Nievas-Rosillo and S. O'Brien and R. A. Ong and N. Park and A. Petrashyk and M. Pohl and E. Pueschel and J. Quinn and K. Ragan and P. T. Reynolds and G. T. Richards and E. Roache and C. Rulten and I. Sadeh and M. Santander and G. H. Sembroski and K. Shahinyan and I. Sushch and S. P. Wakely and R. M. Wells and P. Wilcox and A. Wilhelm and D. A. Williams and T. J. Williamson},
journal= {arXiv preprint arXiv:1904.06324},
year = {2019}
}
备注
Accepted for publication in Nature Astronomy