| 29 | Thoughts on binary sims |
| 30 | |
| 31 | First we have position of primary |
| 32 | |
| 33 | [[latex($\vec{X_p}=R_p [\cos{\Omega t}, \sin{\Omega} t, 0]$)]] |
| 34 | |
| 35 | and velocity of primary as |
| 36 | |
| 37 | [[latex($\vec{v_p}=R_p \Omega [-\sin{\Omega t}, \cos{\Omega t}, 0]$)]] |
| 38 | |
| 39 | The velocity [[latex($v_0$)]] at the surface of the primary [[latex($x_0$)]] can be written as |
| 40 | |
| 41 | [[latex($\vec{v}_0=\vec{v_p}+\hat{x}_0 v_w$)]] |
| 42 | |
| 43 | where |
| 44 | |
| 45 | [[latex($\hat{x}_0 = \frac{\vec{x}_0-\vec{X_p}}{|\vec{x}_0-\vec{X_p}|}$)]] |
| 46 | |
| 47 | And then the velocity is constant along characteristics given by [[latex($\vec{x}-\vec{x}_0 = \vec{v}_0 t$)]] |
| 48 | |
| 49 | Given [[latex($\vec{x}$)]] and [[latex($t$)]] we wish to find [[latex($\vec{x}_0$)]] and [[latex($\vec{v}_0$)]] so that [[latex($\vec{x}-\vec{x}_0 = \vec{v}_0 t$)]] |
| 50 | |
| 51 | substituting the expression for [[latex($\vec{v}_0$)]] we have |
| 52 | |
| 53 | [[latex($\vec{x}-\vec{x}_0 = (\vec{v_p}+\hat{x}_0 v_w) t$)]] |
| 54 | |