Files *A.pdf are sets of all-sky maps for various latitudes. Each set is a sequence of five maps showing the sky for growing detection limits. The detection limit depends on the sky luminance, which is much larger in cities than in true nature. Star areas are proportional to their brightness. File allpdf.zip contains all of them.

The maps are computed assuming a chosen (quite common) attenuation of starlight by the atmosphere. The attenuation depends on the air transparency. The parameter of the chosen attenuation is such, that the stars are assumed to be attenuated by 0.25 mag when in zenith (so called zenith extinction). Then at 30° they are attenuated by 0.5 mag etc., depending on the amount of air between the observer and the star. With excellent transparency (zenith extinction of just 0.18 mag), starlight would be a lot stronger near horizon.

The limit given in the right bottom corner is for the faintness of the starlight as attenuated by the atmosphere, for the stars as they appear.

	Name	Last modified	Size	Description
	Parent Directory		-
	single/	2010-12-18 17:15	-
	allpdf.zip	2010-12-18 17:16	1.6M	indiv. latitude maps
	Orion/	2011-01-06 21:30	-
	Leo/	2011-03-16 23:07	-
	Crux/	2011-01-06 21:30	-
	60A.pdf	2010-12-18 17:15	136K
	50sA.pdf	2010-12-18 17:14	163K
	50A.pdf	2010-12-18 17:15	133K
	40sA.pdf	2010-12-18 17:14	165K
	40A.pdf	2010-12-18 17:15	132K
	30sA.pdf	2010-12-18 17:14	160K
	30A.pdf	2010-12-18 17:15	133K
	20sA.pdf	2010-12-18 17:14	154K
	20A.pdf	2010-12-18 17:15	134K
	10sA.pdf	2010-12-18 17:14	153K
	10A.pdf	2010-12-18 17:14	142K
	0A.pdf	2010-12-18 17:14	149K

The maps containing zenith are planes with the center of projection in zenith. Another maps are cones with the tip at zenith. All maps are equidistant.