PLANET

        [ASTRO\]PLANET [name] [/DRAW [Arg1 ... ArgN]]  [/EPHEMERIS  FileName
    NEW|APPEND] [/QUIET] [/BEAM beam]

    Compute  the  coordinates  of  a Solar System object. Known objects are:
    MOON, SUN, MERCURY, VENUS, MARS, JUPITER, SATURN, URANUS, NEPTUNE. If no
    name  is  entered, all objects are selected. The Option /DRAW is used to
    plot the object symbol on the screen.

    The PLANET command output the planet coordinates (apparent RA,  apparent
    DEC,  Azimuth and Elevation at time of computation) and the sun distance
    (with a warning message if this distance os  lower  than  the  telescope
    limit).  PLANET also indicates the geocentric (DE) and heliocentric (DS)
    distances of the object (in AU), the apparent minor and major  diameters
    (Min and Maj in arcsec), the position angle of the central meridian (PA,
    east from north, in degrees), the brightness temperature (TB in K),  the
    flux  (S  in  Jy)  at the current frequency, the frequency (in GHz), the
    beam (in arcsec), the main beam temperature (Tmb in K),  the  associated
    flux (in Jy) and the planet size convolved with the telescope beam (size
    in arcsec).

    For the Moon, the Sun and Mercury, the brightness temperature is a fixed
    value.   For Mars, the brightness temperature is scaled according to the
    heliocentric distance.  For Venus, the brightness temperature is comput-
    ed  at  the  current  frequency  using a reference value at 100GHz and a
    spectral index.

    As of July 2023, for Jupiter, Saturn, Uranus and Neptune the  brightness
    temperature is interpolated from tabulated values of model spectra. (Be-
    fore that, Jupiter and Saturn brightness temperatures were fixed  values
    while a spectral index was taken into account for Uranus and Neptune).

    The method used to get the planet brightness temperature is given in the
    command output and in the sic variable ASTRO%PLANET%TBTHOD (MODEL =  in-
    terpolation from model, SPIDX = computed from value and spectral index)

    The  accuracy of the planet brightness temperatures as computed in ASTRO
    is estimated to be on the order of 5%.

    The frequency can be entered by  updating  the  variable  FREQUENCY  (in
    GHz).

    PLANET /QUIET suppresses all the printouts on the screen.

    Without  the option /BEAM, the beam used is deduced from the current ob-
    servatory and frequency. User may override this default  by  giving  non
    zero beam size (in arcsec) as an argument of the /BEAM option.

    All  these parameters are also also written in SIC variables, in the AS-
    TRO%PLANET% structure. Just enter EXAMINE ASTRO%PLANET% to  get  a  com-
    plete list of these variables.