Occultations by Pluto and Charon: 1980-1990

D.J. Mink
Harvard-Smithsonian Center for Astrophysics)
A.R. Klemola
Lick Observatory


In order to accurately predict the circumstances of the occultation by Pluto of the star MKP 8 which occurred on 9 June of this year, models of Pluto's and Charon's position relative to the stars were significantly improved. As the reality of that event matched the model to well within a Pluto radius, the circumstances of previously predicted Pluto and Charon occultations were recomputed using the new model. In 1980, Alistair Walker observed an occultation that has been assumed to have been by Charon. The new model shows that it was by Charon. In 1985, Haim Mendelson observed an occultation that may have been by Pluto. The new model shows that Pluto may have been the occulting object, but more work is needed to ascertain whether Mendelson could have discovered Pluto's atmosphere. Unobserved events in 1983 and 1986 have also been checked. Event P9 in the authors' list of Pluto occultations, forecast to occur on 14 June 1989, has been discovered to havebeen caused by a typographic error in the merged plate catalog, so no occultations are predicted to occur through 1990.