Functions:
'Start' and 'Stop' begin and pause the simulation. 'Reset' returns the simulation to time=0. 'Grid' shows a calibrated length scale (in [AU]), centered on the stars' center of mass.
'Labels' identifies the stars and planets.
'Data' toggles the screen's data display.
'Finer' halves the time step size, making the predicted positions approx 16x more accurate, and 'Coarser' doubles the time step, which gives a faster but less accurate simulation. The initial conditions thetastars(0), astars, xplanet(0) and v_y(0) are shown over the scrollbars, which can be used to change them.
During the simulation the screen shows the elapsed time in [yrs], the planet's distance from the stars'
center of mass in [AU], the planet's velocity in [km/sec] and estimated temperature, assuming that it has the Earth's albedo.
Please experiment with different initial conditions by using the scrollbars, then start the simulation and note the fate of the planet. The problem of a backwards-orbiting planet (negative v_y(0)) is expecially interesting.
The Simulation:
The stars are placed in a circular orbit with a separation specified by the scrollbar.
The planet's orbit is then determined by numerically integrating
F=ma
with the specified initial conditions.