Editing Binary star (section)

===Calculating the center of mass in binary stars===
In a simple binary case, the distance ''r''<sub>1</sub> from the center of the first star to the center of mass or [[barycenter]] is given by

<math display="block">r_1 = a \cdot \frac{m_2}{m_1 + m_2} = \frac{a}{1 + \frac{m_1}{m_2}},</math>

where
* ''a'' is the distance between the two stellar centers, and
* ''m''<sub>1</sub> and ''m''<sub>2</sub> are the [[mass]]es of the two stars.

If ''a'' is taken to be the [[semimajor axis]] of the orbit of one body around the other, then ''r''<sub>1</sub> is the semimajor axis of the first body's orbit around the center of mass or ''barycenter'', and {{nowrap|1=''r''<sub>2</sub> = ''a'' − ''r''<sub>1</sub>}} is the semimajor axis of the second body's orbit. When the center of mass is located within the more massive body, that body appears to wobble rather than following a discernible orbit.