The Prediction and Observation of the 1997 July 18 Stellar Occultationby Triton: More Evidence for Distortion and IncreasingPressure in Triton’s Atmosphere

1 Also at Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001-4499. 2 Also at Department of Physics, MIT, and guest observer, Cerro Tololo InterAmerican Observatory, National Optical Astronomy Observatories, operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. 3 Now at Southwest Research Institute, Suite 426, 1050 Walnut St., Boulder, CO 80302. 4 Now at Astronomy Department, Coinell University, Ithaca, NY 14853. A variety of CCD astrometric data was used to predict the location of the path for the occultation of the star we have denoted “Tr176” by Triton, which occurred on 1997 July 18, and was visible from locations in northern Australia and southern North America. A network of fixed and portable telescopes equipped with highspeed photometric equipment was set up to observe the event, with the following observational goals: (i) mapping the central flash (to