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. ***
