Apparent position of a Star

Functions
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.

Parameters

mean_position	Mean position of object
proper_motion	Proper motion of object
JD	Julian Day
position	Pointer 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().