Astronomical Applications Department, U.S. Naval Observatory - NOVASC (Page 13)

VIRTUAL_PLANET

short int virtual_planet (double tjd, short int planet, short int earth,

double *ra, double *dec, double *dis)

PURPOSE:
Computes the virtual place of a planet or other solar system body.

INPUT
ARGUMENTS:
tjd (double)
TDT Julian date for virtual place.
earth (short int)
Body identification number for the Earth.
planet (short int)
Body identification number for desired planet.

OUTPUT
ARGUMENTS:
*ra (double)
Virtual right ascension in hours, referred to mean equator
and equinox of J2000.
*dec (double)
Virtual declination in degrees, referred to mean equator
and equinox of J2000.
*dis (double)
True distance from Earth to planet in AU.

RETURNED
VALUE:
(short int)
0...Everything OK.
>0...Error code from function 'solarsystem'.

Discussion:

See the discussion for function app_planet. Function virtual_planet is identical to app_planet in input

arguments and use. Here, however, the output arguments provide the virtual place of the planet. The virtual
place is essentially the apparent place expressed in the coordinate system of standard epoch J2000.0.