Occultations of faint stars by Neptune and its rings: 1992-1999

There are still many uncertainties concerning the nature of Neptune's rings, and observations of additional occultations of stars by those rings may resolve some of them. As Neptune moves away from the galactic plane during the 1990s, there are fewer stars in its path. The search undertaken by Klemola and Mink (1991, Astron. J. 102, 389-394) has been extended to the limit of their plates, a V magnitude of approximately 15.5, to yield more possible occultations. Circumstances for the close approaches of Neptune to 68 stars during the period from 1992 through 1999 are presented. Seventeen possible occultations of these stars by Neptune's ring arcs were found out of 40 occultations by the ring plane. Photometry of selected candidates has shown that some have a K magnitude brighter than 11.