▁Root ▁albums ▁Category : 2 0 0 2 ▁albums ▁Category : Is land ▁Records ▁albums ▁Category : Al bum s ▁produced ▁by ▁Bill ▁B ott rell <0x0A> </s> ▁In ▁astronom y , ▁the ▁z en ith al ▁hour ly ▁rate ▁( Z HR ) ▁of ▁a ▁meteor ▁show er ▁is ▁the ▁number ▁of ▁met e ors ▁a ▁single ▁observer ▁would ▁see ▁in ▁an ▁hour ▁of ▁peak ▁activity , ▁assumed ▁the ▁conditions ▁are ▁excellent ▁( st ars ▁visible ▁up ▁to ▁magnitude ▁ 6 , 5 ). ▁The ▁rate ▁that ▁can ▁effectively ▁be ▁seen ▁is ▁nearly ▁always ▁lower ▁and ▁decre ases ▁the ▁closer ▁the ▁radi ant ▁is ▁to ▁the ▁horizon . ▁ ▁The ▁formula ▁to ▁calculate ▁the ▁Z HR ▁is : ▁ ▁where ▁ ▁represents ▁the ▁hour ly ▁rate ▁of ▁the ▁observer . ▁ ▁N ▁is ▁the ▁number ▁of ▁met e ors ▁observed , ▁and ▁Te ff ▁is ▁the ▁effective ▁observation ▁time ▁of ▁the ▁observer . ▁ ▁Example : ▁If ▁the ▁observer ▁detected ▁ 1 2 ▁met e ors ▁in ▁ 1 5 ▁minutes , ▁their ▁hour ly ▁rate ▁was ▁ 4 8 . ▁( 1 2 ▁divided ▁by ▁ 0 . 2 5 ▁hours ). ▁ ▁This ▁represents ▁the ▁field ▁of ▁view ▁correction ▁factor , ▁where ▁k ▁is ▁the ▁percentage ▁of ▁the ▁observer ' s ▁field ▁of ▁view ▁which ▁is ▁ob struct ed ▁( by ▁clouds , ▁for ▁example ). ▁ ▁Example : ▁If ▁ 2 0 % ▁of ▁the ▁observer ' s ▁field ▁of ▁view ▁were ▁covered ▁by ▁clouds , ▁k ▁would ▁be