def _calc_stats(tls_results, sde_threshold=5):
    """
    Decide whether a detection is significant. Currently this function simply
    checks if ``results.SDE`` is larger than specified ``sde_threshold``.

    Parameters
    ----------
    tls_results: dict
        The results from the TLS calculations.

    sde_threshold: float
        Threshold for SDE for a detection to be considered significant.

    """
    significant = tls_results.SDE > sde_threshold
    return significant