/*
 * libration.h -- Lunar optical libration (Meeus Ch. 53)
 *
 * Three components of the Moon's apparent wobble:
 *   l  -- optical libration in longitude (degrees, [-8, +8])
 *   b  -- optical libration in latitude (degrees, [-7, +7])
 *   p  -- position angle of the Moon's axis (degrees)
 */

#ifndef PG_ORRERY_LIBRATION_H
#define PG_ORRERY_LIBRATION_H

typedef struct
{
	double l;	/* libration in longitude, degrees (optical + physical) */
	double b;	/* libration in latitude, degrees (optical + physical) */
	double p;	/* position angle of axis, degrees */
	double _tau;	/* physical libration correction in longitude, degrees */
	double _rho;	/* physical libration correction in latitude, degrees */
} lunar_libration;

void compute_lunar_libration(double jd, lunar_libration *lib);

#endif /* PG_ORRERY_LIBRATION_H */