The Occultation of Beta Scorpii by Jupiter and Io. I. Jupiter

Three one-dimensional area-scanning photometers under computer control, equipped to observe in one color, were taken to observing stations in Australia, India, and Africa to observe the occultation of the Beta Scorpii system by Jupiter on 13 May 1971. Six high-quality light curves were obtained; three of the occulta- tions of the brighter component Beta Sco A and three of Beta Sco C. The mean scale height of the Jovian upper atmosphere is 32+6 km near - 100 zenographic latitude, 31+2 km at 470 zenographic latitude, and 24+2 km at 570 zenographic latitude. The determination of the atmospheric scale height is highly sensitive to the background level subtracted, providing a possible explanation of an earlier result by Baum and Code placing the scale height at about 8 km. Correlated departures of the light curve from a theoretical isothermal curve are reproduced in the three bright-star curves, and are thus not due to random density fluctuations in the Jovian atmosphere, but rather due to global stratification. Details of the stratification, which includes at least a number of warm layers, are examined by deconvolution of the light curves. There is evidence for a high temperature (T>300 K) thermosphere on two of the bright-star light curves.