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Institut für Astronomie und AstrophysikAbteilung AstronomieSand 1, D-72076 Tübingen, Germany |
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binarycor,time,asini=asini,porb=porb,eccentricity=ecc,omega=omega_d, $
t90=t90,t0=t0, pporb=pporb,limit=limit,maxiter=maxiter
time : event time (MJD)
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
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)
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.
$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
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