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B. L. Cooper (Oceaneering Space Systems), H. A. Zook (NASA Johnson Space Center), J. M. Hahn (Lunar and Planetary Institute), A. E. Potter (NSO)
Excellent photographs of the inner zodiacal light, using the Moon as an occulting disk, have been obtained with the Clementine star-tracker cameras. With exposures that vary from 50 milliseconds to 700 milliseconds, with a dynamic range of 256 for each exposure, and with a 28.9 degree by 43.4 degree field of view, the Clementine cameras have recorded the zodiacal light brightness from 1 degree (the solar F- corona) to in excess of 20 degrees from the Sun. Problems of proper removal of thermal background electrons, of 'streak' removal, and of absolute brightness calibration, have been earlier described and resolved (1). The problem of correcting for the non-uniform response of the star-tracker cameras to a field of uniform brightness is now also largely resolved, and photometrically accurate maps of the inner zodiacal light intensity isophotes are now obtainable. These maps represent a major advance in obtaining zodiacal light brightnesses, in both heliocentric longitude and latitude, over previous studies in this region of the sky.
The spatial density of dust grains, as a function of both ecliptic longitude and latitude relative to the Sun, are obtained using well-understood integral inversion procedures. The relation of the symmetry plane of the dust density to the ecliptic plane will be analyzed in terms of gravitational perturbations by Jupiter and the inner planets.
(1) Zook et al., LPSC 28, 1635-1636, 1997.
The author(s) of this abstract have provided an email address for comments about the abstract: bcooper@oss.oceaneering.com