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/***************************************************************************
kspluto.h - K Desktop Planetarium
-------------------
begin : Mon Sep 24 2001
copyright : (C) 2001 by Jason Harris
email : kstars@30doradus.org
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#ifndef KSPLUTO_H
#define KSPLUTO_H
#include "ksasteroid.h"
/**@class KSPluto
*A subclass of KSAsteroid that represents the planet Pluto. Now, we
*are certainly NOT claiming that Pluto is an asteroid. However, the
*findPosition() routines of KSPlanet do not work properly for Pluto.
*We had been using a unique polynomial expansion for Pluto, but even
*this fails spectacularly for dates much more remote than a few
*hundred years. We consider it better to instead treat Pluto's
*orbit much more simply, using elliptical orbital elements as we do
*for asteroids. In order to improve the long-term accuracy of Pluto's
*position, we are also including linear approximations of the evolution
*of each orbital element with time.
*
*The orbital element data (including the time-derivatives) come from
*the NASA/JPL website: http://ssd.jpl.nasa.gov/elem_planets.html
*
*@short Provides necessary information about Pluto.
*@author Jason Harris
*@version 1.0
*/
class KStarsData;
class KSPluto : public KSAsteroid {
public:
/**Constructor. Calls KSAsteroid constructor with name="Pluto", and fills
*in orbital element data (which is hard-coded for now).
*@p kd pointer to the KStarsData object
*@p fn filename of Pluto's image
*@p pSize physical diameter of Pluto, in km
*/
KSPluto(KStarsData *kd, TQString fn="", double pSize=0);
/**Destructor (empty) */
virtual ~KSPluto();
protected:
/**A custom findPosition() function for Pluto. Computes the values of the
*orbital elements on the requested date, and calls KSAsteroid::findGeocentricPosition()
*using those elements.
*@param num time-dependent values for the desired date
*@param Earth planet Earth (needed to calculate geocentric coords)
*@return true if position was successfully calculated.
*/
virtual bool findGeocentricPosition( const KSNumbers *num, const KSPlanetBase *Earth=NULL );
private:
//The base orbital elements for J2000 (these don't change with time)
double a0, e0;
dms i0, w0, M0, N0;
//Rates-of-change for each orbital element
double a1, e1, i1, w1, M1, N1;
};
#endif
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