Visibility of Luna and Lunar Crescent

cxnibircd in n8 9 ir is mr.d lhnl aI $le dip r = 0 d€gees lh. ninimM dliNd€s for
dif,cFnt vidrh ces@t3 @ girq
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Tbh hcms Aar rbe bndrh$ of lh. sky ar rhe* atrirudes (r) G we .s rhe brishrne$ of
th€ cBent of@ftsponding widrh when lhe su hdjul $r. I. ord{ dul l,rtc ce$. is
rt 16r a bright s the sty wilh dftEding ahiludc rh. c@e nusl b. wider ud sidc,.
Tnes ar€ thc sanins poinls of rh. vnibilny c!ryes fial aG aU shaqty d(rtsing
f!.crions ol the sotar dip, That heons lhar not only the brighh*s oi cc$e bul $e
brighr&s of sky (har cqul alons lbcs cwa) borh diminish sh!+t, wirh $e
inc@ine st& deFEssion.
Th€r.forc, for larger values ot r rh. ee$ent of sne brightne$ @ b. $en at
lower od loer alftudc ,. Tlw arc al$ the sianing points or rn€ cums ttat show lhc
b.h.viou of, + s {sh ofglribd. of M@n ed lh. sot{ depb) agaiGr th. $tar dept r
Ahhou8h the sm of th. atlitude /, of $e cresced dd the r me $lar dip Eoains alnost
consbrt 4 $e ce*enr gos doM dese cw6 coftsponding to fix€d crcsnt width
ed thcEby ro nx€d brighhess. As (he atrirudc of ce$.hl daca*s 0r. sky brighrness
n4l d<Eases bul rhen closer lo rhc hodzon the \isibilill sbns deo€4in8. Tnus rhese
cuNes fir$ sr.d decrsing with inc,eding !, reach d hininud ed lhcn sl,n i.cre6ing.
This in facr shows the raryjng @slrst of the brigl JEs, ol lhe crcsn md lhar of te
sky. with smatler r and td8.! , lhe contAl is ag.insl dc v6rb,tity, As , incpses dd /l
decEass $e contFsr beo66 favoudbt. fo! vhibitity of c!€$enr. However. 6 /,
funho d€qees rhc @nusl again bc@Des dfavombt. Ior v$ibility.
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