Analysis of comet C/1969 Y1 parameters using isophote structural modeling

This work is devoted to the construction of a brightness structural model of the long-period comet Bennett C/1969 Y1. This comet belongs to the comets of the Jupiter family (JF) and has a Tisserand’s parameter T > 2. Determining the brightness characteristics of the comet has been one of the most important goals of cometary observations over the past century. The complexity of such studies lies in the fact that we are dealing with extended sources moving relative to background stars. The problem of obtaining reliable estimates of the distribution of brightness parameters (BPs) for long-period comets also remains especially important, because for many of them observations were made back in the days when high-precision methods, such as CCD-matrices and other technical tools, were not available. At the same time, most of the determined stellar magnitudes of long-period comets were related to the gaseous coma surrounding the comet’s nucleus, and not to the comet’s nucleus itself. At the same time, cosmic ultraviolet observations of comets in the Lyman-alpha hydrogen lines made it possible to obtain very important data for estimating the emission of H₂O by the cometary nucleus, as well as other types of molecules (e.g. C2, C3, CN, OH). In the presence of dependencies between the productivity of the H₂O cometary nucleus and its brightness characteristics, the determination of BPs of cometary nuclei has acquired a new meaning. However, the dependence of the size of the nucleus on its BPs is not linear, since there is a correlation with the albedo of the surface of the nucleus. In this work, BPs and albedo for comet Bennett C/1969 Y1 are studied. Taking into account the data obtained and the solution of the described problems, we applied the author’s isophote method to analyze the structure of the brightness characteristics of Bennett C/1969 Y1.