Wrong uncertainty on V-band extinction

[mdecleir]

When calculating the band extinctions, there should be a special consideration for the V-band.
E(V-V) will be exactly zero, however, the uncertainties on the V-band extinction are calculated as 2 times the square of the uncertainty on the V-band magnitude. I believe the uncertainty should be 0 instead.

measure_extinction/measure_extinction/extdata.py

Lines 360 to 369 in 3e94cee

	red_mag = red.data["BAND"].get_band_mag(pband_name)
	comp_mag = comp.data["BAND"].get_band_mag(pband_name)
	if (red_mag is not None) & (comp_mag is not None):
	ext = (red_mag[0] - red_rel_band[0]) - (comp_mag[0] - comp_rel_band[0])
	unc = np.sqrt(
	red_mag[1] ** 2
	+ red_rel_band[1] ** 2
	+ comp_mag[1] ** 2
	+ comp_rel_band[1] ** 2
	)