def forcedEccentricity(binary_sys,r):
    """
    Given a binary class object and an array of radial points in the disk, 
    compute the forced eccentricity defined by Moriwaki et al. 2004 
    eqn 9 to first order.  Extra factor of 2 to give e_pumped instead
    of e_forced.  Note: This only applies when e_binary != 0 and when
    m2/(m1 + m2) != 0.5 (i.e. only applies for eccentric, non-equal mass
    binary)
    
    Parameters
    ----------
    binary_sys : binary.Binary class object
    r : array
        array of radii in AU
        
    Returns
    -------
        e_forced : array
            array of len(r)
    """
    mu = binary_sys.m2/(binary_sys.m1 + binary_sys.m2)
    return (5./2.)*(1.0 - 2.0*mu)*binary_sys.e*binary_sys.a/r