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Mallama 1993
Mallama, A. (1993). Photometric models for Galilean satellite astrometry. Journal of Geophysical Research 98: doi: 10.1029/93JE01333. issn: 0148-0227.

Models for the Galilean satellites have been used to determine the distribution of brightness on their surfaces. The results indicate that the distance between a satellite's photocenter and its center-of-figure can reach 209 km for Io, 221 km for Europa, 303 km for Ganymede, and 255 km for Callisto. Astrometry of the satellites can achieve much greater precision than this, so a correction for the photocentric offset should be applied. This paper presents tables of photocentric offsets for the Galilean satellites as functions of orbital longitude and solar phase angle. The estimated accuracy of these corrections is 32 km for Io, 45 km for Europa, 49 km for Ganymede, and 40 km for Callisto, but the latter two may be optimistic. The satellite ephemerides derived from astrometry are essential for interpreting observations of variable phenomena on Io, such as volcanic activity inferred from IR observations taken during occultations of the satellite. Accurate ephemerides are also critical to spacecraft navigation. ¿ American Geophysical Union 1992

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Abstract

Keywords
Solar Physics, Astrophysics, and Astronomy, Celestial mechanics, Planetology, Solid Surface Planets, Orbital and rotational dynamics, Planetology, Solid Surface Planets, Instruments and techniques
Journal
Journal of Geophysical Research
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Publisher
American Geophysical Union
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