How to set the value of some Parameters in the "Model Parameters" screen?

[HeBe-lab]

Hello teacher,I would like to ask you about this article"NEW TOOL WITH GUI FOR FITTING O-C DIAGRAMS"How are the values of such parameters as Q,a_sin_i3,e3,w3,t03,p3 obtained in?

[pavolgaj]

I don't understand your question. These parameters are computed during fitting your O-C diagram. If using GA (genetic algorithms) fitting, they're obtained as the best solution (minimal error) from all generations and individuals. For MCMC (Markov chain Monte Carlo) method, they're calculated as mean values of the final distributions.

[HeBe-lab]

Thank you for your reply,Maybe I didn't describe my question clearly.My my question is as follows.
How are the values of Q,a_sin_i3,e3,t03 and P3 in Figure 2 of your article filled or set? Then I want to know why the range of the parameter T03 in the following picture is 40000.0 to 50000.0 and why the range of P3 is 3000.0 to 5000.0?On what basis are they set?

[pavolgaj]

The ranges of the parameters are set according to the fitted O-C diagram. The values in Fig. 2 are examples for the used O-C diagram of star AD And (Fig. 3).

To setting individual ranges:

1. On this O-C diagram (Fig. 3), you can see that the period of the changes is about 4000 days. So, the limits for period P3 is 3000 to 5000 (some interval about guessed value - to be sure that correct value is there).
2. I use to set an interval for t03 from approx. time t0 (for the binary) to time t0+max(P3) - interval with a width equal to max. value of P3 (in its range) started in a time t0. So, it was enough to set t03 from 40000 to 45000 in the paper. I wanted only to show there that the searching range could be also bigger.
3. For eccentricity e3, I always use the range 0 to 1 as a first guess. If it doesn't work, I change it in the next steps - e.g. to 0-0.5.
4. Parameter Q describes the quadratic changes on the O-C diagram. Its value is very small 1e-10 and smaller.
5. The most difficult is to set the range for a_sin_i3. It changes the amplitude of O-C (see eq. 6). You can estimate its value as a_sin_i3=K3*c and set the range according to it. But, I think it's simpler to set some interval (e.g. 1-5), try to fit O-C with a small number of iterations and see the result - the shape of the model curve and the value of a_sin_i3. Then, you can change the given range according to it.

Did I help you? Is it more clear, now?

[HeBe-lab]

I see.Thank you for answering my questions.