Astronomical Applications Department, U.S. Naval Observatory - NOVASC (Page 12)

LOCAL_STAR

short int local_star (double tjd, short int earth, double deltat,
fk5_entry *star, site_info *location,

double *ra, double *dec)

PURPOSE:
Computes the local place of a star, given its mean place, proper
motion, parallax, and radial velocity for J2000.0, and the
location of the observer.

INPUT
ARGUMENTS:
tjd (double)
TDT Julian date for local place.
earth (short int)
Body identification number for the Earth.
deltat (double)
Difference TDT-UT1 at 'tjd', in seconds.
*star (struct fk5_entry)
Pointer to catalog entry structure (defined in novas.h).
*location (struct site_info)
Pointer to structure containing observer's location (defined
in novas.h).

OUTPUT
ARGUMENTS:
*ra (double)
Local right ascension in hours, referred to mean equator and
equinox of J2000.
*dec (double)
Local declination in degrees, referred to mean equator and
equinox of J2000.

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

Discussion:

See the discussion for function topo_star. Function local_star is identical to topo_star in input

arguments and use. The local place is essentially the topocentric place expressed in the coordinate system
of standard epoch J2000.0.