▁dog " ▁in ▁Greek , ▁as ▁it ▁r ises ▁an ▁hour ▁before ▁the ▁" D og ▁Star ", ▁Si ri us , ▁of ▁Can is ▁Major . ▁It ▁is ▁a ▁binary ▁star ▁system , ▁consisting ▁of ▁a ▁yellow - white ▁main ▁sequence ▁star ▁of ▁spectral ▁type ▁F 5   IV - V , ▁named ▁Pro cy on   A , ▁and ▁a ▁faint ▁white ▁d war f ▁companion ▁of ▁spectral ▁type ▁DA , ▁named ▁Pro cy on   B . ▁Pro cy on   B , ▁which ▁or bits ▁the ▁more ▁massive ▁star ▁every ▁ 4 1 ▁years , ▁is ▁of ▁magnitude ▁ 1 0 . 7 . ▁Pro cy on   A ▁is ▁ 1 . 4 ▁times ▁the ▁Sun ' s ▁mass , ▁while ▁its ▁smaller ▁companion ▁is ▁ 0 . 6 ▁times ▁as ▁massive ▁as ▁the ▁Sun . ▁The ▁system ▁is ▁▁ ▁from ▁Earth , ▁the ▁short est ▁distance ▁to ▁a ▁northern - hem is phere ▁star ▁of ▁the ▁first ▁magnitude . ▁ ▁G ome isa , ▁or ▁B eta ▁Can is ▁Minor is , ▁with ▁a ▁magnitude ▁of ▁ 2 . 8 9 , ▁is ▁the ▁second - br ight est ▁star ▁in ▁Can is ▁Minor . ▁L ying ▁ ▁from ▁the ▁Sol ar ▁System , ▁it ▁is ▁a ▁blue - white ▁main ▁sequence ▁star ▁of ▁spectral ▁class ▁B 8   V e . ▁Although ▁f ain ter ▁to ▁Earth ▁obser vers , ▁it ▁is ▁much ▁br ighter ▁than ▁Pro cy on , ▁and ▁is ▁ 2 5 0