libnova  v 0.16.0
Apparent position of a Star


void ln_get_apparent_posn (struct ln_equ_posn *mean_position, struct ln_equ_posn *proper_motion, double JD, struct ln_equ_posn *position)
 Calculate the apparent position of a star. More...

Detailed Description

The apparent position of a star is it's position as seen from the centre of the Earth.

All angles are expressed in degrees.

Function Documentation

void ln_get_apparent_posn ( struct ln_equ_posn mean_position,
struct ln_equ_posn proper_motion,
double  JD,
struct ln_equ_posn position 

Calculate the apparent position of a star.

mean_positionMean position of object
proper_motionProper motion of object
JDJulian Day
positionPointer to store new object position

Calculate the apparent equatorial position of a star from its mean equatorial position. This function takes into account the effects of proper motion, precession, nutation, annual aberration when calculating the stars apparent position. The effects of annual parallax and the gravitational deflection of light (Einstein effect) are NOT used in this calculation.

References ln_get_equ_aber(), ln_get_equ_pm(), and ln_get_equ_prec().