def L_nu_from_sfr(sfr):
    """Use Kennicutt (1998) conversion from UV luminosity to star formation rate.

    Parameters
    ----------

    sfr:
        The SFR in Msun/year.

    Returns
    -------

    luminosity:
        the luminosity in units of ergs s^-1 Hz^-1 anywhere between
        1500-2800 Angstroms.

    Notes
    -----

    Kennicutt (1998ARA&A..36..189K) says:

       SFR/(MSun/year) = 1.4 * 10^-28 (L_nu/ergs s^-1 Hz^-1)

    where L_nu is the UV luminosity anywhere between 1500-2800 Angstroms.
    """
    return sfr / 1.4e-28
