import math


def calc_4piDsquared(distance, distance_err):
    """Calculates :math:`4\\pi D^2`, to convert flux to luminosity.

    Args:
        distance (float): The distance to the supernova in centimeters.
        distance_err (float): The uncertainty in the distance to the supernova.

    Returns:
        tuple: A tuple containing the :math:`4 \\pi D^2`, and the uncertainty of this number.

        (4piDsquared, uncertainty)
    """
    fourPiDsquared = 4.0 * math.pi * distance**2.0
    fourPiDsquared_uncertainty = 8.0 * math.pi * distance * distance_err

    return fourPiDsquared, fourPiDsquared_uncertainty