▁the ▁const ell ation ▁C yg n us . ▁Its ▁apparent ▁magnitude ▁is ▁ 5 . 1 8 . ▁Loc ated ▁around ▁ ▁distant , ▁its ▁primary ▁is ▁a ▁yellow ▁super gi ant ▁of ▁spectral ▁type ▁F 6 I b , ▁a ▁massive ▁star ▁that ▁has ▁used ▁up ▁its ▁core ▁hydro gen ▁and ▁is ▁now ▁f using ▁heav ier ▁elements . ▁ ▁Y ellow ▁super gi ants ▁are ▁usually ▁variable , ▁often ▁Class ical ▁C ep heid ▁variables , ▁but ▁ 3 5 ▁C yg ▁is ▁notable ▁for ▁having ▁an ▁especially ▁constant ▁bright ness . ▁▁ 3 5 ▁C yg ▁is ▁a ▁single - lined ▁spect ro scop ic ▁binary ▁with ▁a ▁period ▁of ▁ 2 , 4 4 0 ▁days ▁( over ▁ 6 ▁years ). ▁ ▁The ▁secondary ▁cannot ▁be ▁seen ▁directly , ▁nor ▁can ▁its ▁spectral ▁lines ▁be ▁identified ▁but ▁the ▁overall ▁spectrum ▁can ▁be ▁match ▁by ▁a ▁combination ▁of ▁an ▁F 4 ▁super gi ant ▁and ▁a ▁less ▁l umin ous ▁B 6 . 5 ▁star . ▁ ▁References ▁ ▁Category : C yg n us ▁( const ell ation ) ▁C yg ni , ▁ 3 5 ▁Category : F - type ▁super gi ants ▁Category : S pect ro scop ic ▁bin aries ▁Category : B - type ▁main - sequence ▁stars ▁ 7 7 7 0 ▁ 1 9 3 3 7 0 ▁B D + 3 4 ▁ 3 9 6 7 ▁ 1 0 0 1 2 2 <0x0A> </s> ▁Pav la ▁Ben ý