def vcirc(m1,m2,a):
    """ Circular orbital velocity of m2 about m1 at distance a
        m1 in Solar masses
        m2 in Jupiter masses
        a in AU
        returns v in m/s
    """

    # http://en.wikipedia.org/wiki/Circular_orbit

    mu = G * ((m1*msol) + (m2*mjup))
    vcirc = np.power((mu / (a*au)), 0.5)
    return(vcirc)
dataset/ETHPy150Open mkenworthy/exorings/disk_sim.py/vcirc/original