A NEW TOOL FOR PROVIDING OBSERVATIONS OF PLANETARY SATELLITES WITH EPHEMERIDES

A tool for furnishing observations of planetary satellites with epheme rides has been developed and is being distributed for practical use. A new approach to obtaining ephemerides has been adopted. Instead of ta bles with satellite coordinates, a computer program with a user-friend ly interface has been written which displays the apparent positions of planetary satellites in graphical and digital forms. The coordinates are not calculated in advance to be stored; rather, the program comput es them instantaneously for any given time. Visibility conditions for a planet at a specified observatory, including topocentric coordinates of the planet, Sun, Moon, and phases of the Moon are simultaneously d etermined and displayed. Mutual occultations and eclipses of the satel lites are automatically detected, and decline in their brightness is c omputed during these events.