Keywords: astro

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## Solar system bodies

The `PLANET name` command is similar to the `SOURCE` command, but the object must be a Solar System body. No catalog is used. Known objects are: SUN, MOON, MERCURY, VENUS, MARS, JUPITER, SATURN, URANUS, NEPTUNE. `PLANET` with no argument compute positions for all these objects.

Just like `SOURCE`, the `PLANET` command updated a number of `ASTRO` global variables (`RA`), `DEC`, `AZIMUTH`, `ELEVATION`). A structure called `astro%planet%` is also created, and contains all output values of the `PLANET` command.

In addition to the position, information is given on the planet's apparent size and position angle, its brightness temperature and flux at (sub)millimeter wavelengths, at the current frequency.

- The observing frequency (in GHz) is updated by modifying the value of the variable `FREQUENCY`. Default is 100 GHz.
- The beam of the telescope is computed by ASTRO, using the antenna diameter associated to the selected observatory (Table ). This can however be modified by the user, by setting the `BEAM` variable to a non-zero value. The read-only `PRIMBEAM` variable contains the value actually used in the computation.

Next: Precession Up: Computing source positions Previous: Source selection Contents