Discrete and continuous Franck Condon factors of the Mg<sub>2</sub> A<sup>1</sup>Σ<span style=text-decoration:overline><sub>u</sub><sup>+</sup></span>-X<sup>1</sup>Σ<span style=text-decoration:overline><sub>g</sub><sup>+</sup></span> system and their J dependence.