Posted October 29, 2020 by J. Douglas Patterson
The Binary Star System Simulator is continuing to develop and offer more pedagogical usefulness. Changes from the first version include a reworking of the UI and editable parameters, the inclusion of a formula sheet for reference, and an example of a worked out problem.
My initial idea was to allow the user to construct a system of their choice and then work the problem backward using the period and velocities to get the masses and separation they entered at first. While I still have this implementation, it does not achieve the learning goals I had in mind. Instead, the simulator now depicts a system in which the stellar masses and orbital period are selected by random and the user is asked to calculate and enter the values for the individual stellar masses and the average separation. When the correct values are entered, the text turns green and a chime plays. If an incorrect value is entered, the text turns read and a buzzer plays. A fanfare accompanied by cheers and applause play when all entered values are correct.
To serve as a reminder for the user, a window showing all of the pertinent formulae for solving for the masses of two stars in a binary system can be toggled on and off. Pressing the "F" key toggles its visibility state with its initial state being hidden. The user will still need to perform some algebra with these provided formulae.
To show the process of how to solve for the masses of two stars in a binary system, there is a window that can be displayed and hidden solving for the masses of the two stars of the Sirius system. The problem begins with the same data that is provided by the simulator, the two velocities and the orbital period. The example then steps the user through the process of finding the average separation, the ratio of the masses of the two stars, the total mass of the two stars, and how to solve for the individual masses.