ON THE NOVA RATE IN THE GALAXY

The Galactic nova rate is poorly known, with estimates in the literatu re ranging from as few as 11 to as many as 260 yr(-1). At the lower en d of the spectrum (less than or similar to 50 yr(-1)), the predictions are based on scalings from extragalactic nova surveys, while estimate s based on extrapolations of Galactic nova observations suggest rates that are significantly higher, in the range 50-100 yr(-1) or more. In an attempt to reconcile this difference, the nova rate, based on Galac tic nova observations, is recomputed. If the stellar mass distribution is axisymmetric about the Galactic center, a new estimate of the Gala ctic nova rate of similar to 35 +/- 11 yr(-1) is deduced. Although thi s value is marginally consistent with the highest estimates based on e xtragalactic surveys, the agreement is not entirely satisfactory. It i s pointed out that a departure from axial symmetry, such as that cause d by the presence of a Galactic bar, can potentially lower the estimat ed nova rate (perhaps approaching 50%) if the bar is sufficiently larg e, and has its long axis pointed toward the Sun. Alternatively, or per haps in addition, it is possible that previous extragalactic surveys m ay have missed a significant fraction of novae (up to a factor of simi lar to 2) because of extinction internal to the galaxies. If this latt er possibility can be ruled out, for example, through infrared surveys of nearby galaxies, the Galactic nova observations may provide additi onal support for the existence of a Galactic bar.