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Abteilung Astronomie

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binarycor.pro Source code in binarycor.pro


NAME: binarycor.pro PURPOSE: Removes the influence of the doublestar motion for circular or eliptical orbits. CATEGORY: timing tools
Calling Sequence
   binarycor,time,asini=asini,porb=porb,eccentricity=ecc,omega=omega_d, $
              t90=t90,t0=t0, pporb=pporb,limit=limit,maxiter=maxiter
Input Parameters
               time   : event time (MJD)
Keyword Parameters
               asini  : Projected semi-major axis [lt-secs], Mandatory
               porb   : Orbital period at the epoch [days], Mandatory
               eccentricity : Eccentricity, (0<=e<1)
               omega: Longitude of periastron [degrees], mandatory
       the epoch is given by one of the following:
               T0     : epoch for mean longitude of 0 degrees
                        (periastron, MJD)
               T90    : epoch for mean longitude of 90 degrees (MJD)
           T90 and T0 have to be in days and in the same time
           system as time (e.g. JD or MJD)
         Circular orbits:
              * if time of lower conjunction Tlow is known, set
                T0=Tlow and omega=0
              * if time of ascending node is known, Tasc, set
                T90=Tasc and omega=0
              * if time of mid eclipse is known, Tecl, set
                T0=Tecl-0.25*porb and omega=0
Optional Input Parameters
               pporb: rate of change of the orbital period (s/s)
               limit: absolute precision of the correction of the
                      computation (days, default: 1D-6)
               maxiter: stop Newton-Raphson iteration after maxiter
                      steps if limit is not reached (default: 20)
Output Parameters
               time is updated to the time in the barycenter of the
               double star
   For each time, the z-position of the emitting object is computed
   and the time is adjusted accordingly. This is iterated until
   convergence is reached (usually only one iteration is necessary,
   even in high elliptic cases,
   Follows equations from Hilditch's book and has also been
   checked against fasebin/axBary. All codes give identical results,
   (to better than 1d-7s) as checked by a Monte Carlo search using
   1d7 different orbits.

Revision History
 $Log: binarycor.pro,v $
 Revision 1.6  2006/03/31 10:42:29  wilms
 corrected instructions for circular orbits (prompted by Dmitry Klochkov)
 Revision 1.5  2005/05/14 20:46:39  wilms
 removed special case for circular orbits since this used different
 conventions for the orbit zero point. For this version of the code,
 results for ecc=epsilon and ecc=0 will be the same. Unfortuntely this
 breaks the backwards compatibility.
 Revision 1.4  2005/05/14 13:43:32  wilms
 Corrected erroneous computation of mean anomaly for eccentric orbits.
 Revision 1.3  2005/02/23 09:46:22  wilms
 removed redundant check for t90/t0
 Revision 1.2  2005/02/18 20:40:33  wilms
 * added proper treatment of t90 for elliptical orbits
 * cleaned up the equations for elliptical orbits (removed excessive parentheses)
 Revision 1.1  2004/08/05 12:27:50  wilms
 rewrite of dblstarcor, orbital elements now given as keyword parameters,
 several speed-ups, further consistency checks.
 Verification that the equation for z is correct.
 Revision 1.3  2002/09/09 14:58:27  wilms
 removed debugging statement; several cosmetic changes
               Version 1.0, 1997/01/09, Deepto Chakrabarty, Caltech/MIT
               Version 1.1, 1999/11/11, Patrick Risse IAAT
                           - Include the optional Input of pporb
                           - abort criteria for the iteration

Last modified by pro2html on 2006 April 01 at 03:10 UTC

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Jörn Wilms (wilms@astro.uni-tuebingen.de)
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