moon [rise=] [set=] [ut=] [date=] [geocentric] [noelev]This program calculates the current topocentric position of the moon using a subset of Browns formulation (Brown, Ernest, W. Tables of the Motion of the Moon Yale Univ. Press 1919) as selected by Jerome Hudson. The rms error compared to positions found the Astronomical Almanac for 1990 appears to be on the order of .01 degree. This method is about ten times more accurate than the low precision formula quoted in the blue book. Unless the geocentric option is used the the position is corrected for lunar parallax; this term can be up to one degree.
The output contains a line like.
22:14:10.53 -13:21:16 2005.858 moon 42.1 0.57Where the first two fields are the RA and Dec, the next is the coordinate equinox (read from the system clock), the fourth is the name of the object, the fifth is the number of degrees that the moon is above the horizon and the last is the illumination of the moon, where 0.0 is new and 1.0 is full.
The program can also calculate the Universal time at which the moon reaches a given altitude. In this mode of operation, the output will be a single field in hh:mm:ss format. No corrections for refraction are made.
The observatory longitude is determined from the telescope server using the rctel command (Section 5.11.4).