RUI: An Observational Study of Novae in Differing Stellar Populations

将开展观测项目，研究邻近星系中新星的空间分布和爆发特性。这项研究的长期动机是为了更深入地了解潜在恒星群对紧密双星系统的形成、演化和性质的影响。在紧密的双星系统中，新星的研究非常适合这项任务，因为新星是明亮的（Mv约为-6至-9），很容易识别（由于它们的爆发性质），并且数量相当多（银河系新星率估计为每年几十个）。不幸的是，尽管对银河系新星的观测跨越了本世纪的大部分时间，但人们对新星的空间分布和数量知之甚少，特别是对一般的近距离双星。从表面上看，现有的银河系数据表明，新星主要属于一个古老的盘状星族，但也可能存在一个独特的星族II，或“凸起”新星成分。然而，很难从银河系的数据中确定两种不同的新星群的存在，因为很明显，由于我们在银河系中的位置，这些数据有很大的偏差。偏差的主要来源是星际吸收，星际吸收使大多数新星在我们的视野中变得模糊，并导致距离的不确定性，从而导致观测到的相对一小部分银河系新星的空间分布的不确定性。研究新星群以及确定新星群差异是否会影响其爆发特征的最佳方法是测量外星系中新星的爆发频率、衰减率和空间分布。作为研究的一部分，将测量星系M33、M81和M31的外盘区域的新星频率和空间分布。除了测量空间分布和新星率外，还将测量M31 e盘中新星的b波段光曲线，并将其与已发表的凸起新星的光曲线进行比较，以研究由于潜在恒星群的变化可能存在的任何差异。在这个项目中，将会有本科生和硕士生参与观测和观测数据的化简。＊＊＊

AST-9731641 Shfter An observational program will be carried out to study the spatial distribution and outburst properties of novae in nearby galaxies. The long-range motivation of the study is to acquire a deeper understanding of the effect the underlying stellar population has on the formation, evolution, and properties of close binary systems. Among close binary systems, the study of novae are ideally suited to this task because novae are luminous (Mv about -6 to -9), readily identifiable (due to their eruptive nature), and reasonably numerous (the Galactic nova rate is estimated to be several dozen per year). Unfortunately, despite observations of Galactic novae spanning most of this century, little is known about the spatial distribution and population of novae, in particular, and close binaries, in general. Taken at face value, the available Galactic data suggest that novae belong primarily to an old disk population, but that there may exist a distinct Population II, or "bulge" nova component as well. The existence of two distinct populations of novae is difficult to establish from Galactic data, however, as it is clear that these data are heavily biased by virtue of our position within the Galaxy. The major source of bias results from interstellar absorption, which obscures most novae from our view, and causes uncertainty in the distances and thus uncertainty in the spatial distribution of the relatively small fraction of Galactic novae that are observed. The best approach to studying the population of novae, and for establishing whether population differences may affect their outburst characteristics, is to measure the outburst frequency, fade rates, and spatial distribution of novae in external galaxies. As part of the research to be carried out, the frequencies and spatial distributions of novae will be measured for the galaxies M33, M81, and the outer disk regions of M31. In addition to measuring spatial distributions and nova rates, B-band light curves of novae in th e disk of M31 will be measured and compared with published light curves of bulge novae in order to study any differences that may exist due to the variation in the underlying stellar population. There will be undergraduate students and master's degree students involved in the observations and data reduction of the observations in this project. ***