▁is ▁radi ating ▁ 1 , 1 0 0 ▁times ▁the ▁Sun ' s ▁lum inos ity ▁from ▁its ▁photos phere ▁at ▁an ▁effective ▁temperature ▁of ▁ 7 , 6 1 2   K . ▁ ▁The ▁surrounding ▁g ase ous ▁disk ▁st ret ches ▁out ▁to ▁at ▁least ▁ 1 5 ▁times ▁the ▁star ' s ▁radius ▁and ▁is ▁nearly ▁aligned ▁with ▁the ▁line ▁of ▁sight ▁from ▁the ▁Earth , ▁having ▁an ▁estimated ▁incl ination ▁of ▁. ▁Some ▁time ▁between ▁ 1 9 3 1 ▁and ▁ 1 9 3 5 , ▁the ▁disk ▁became ▁active ▁and ▁has ▁remained ▁so ▁since ▁that ▁time , ▁becoming ▁the ▁subject ▁of ▁multiple ▁studies . ▁The ▁unusual ▁asym met ry ▁in ▁its ▁emission ▁lines ▁have ▁led ▁to ▁it ▁being ▁mis class ified ▁as ▁a ▁super gi ant ▁of ▁type ▁B 8   I a / I b ▁by ▁S IM B AD ▁and ▁others . ▁This ▁asym met ry ▁displays ▁quasi - period ic ▁behavior ▁of ▁the ▁type ▁found ▁in ▁about ▁a ▁third ▁of ▁all ▁Be ▁stars , ▁with ▁a ▁period ▁of ▁about ▁ 1 0 ▁to ▁ 1 7 ▁years . ▁This ▁variation ▁may ▁arise ▁from ▁the ▁pre cess ion ▁of ▁a ▁one - ar med ▁density ▁wave ▁in ▁the ▁disk . ▁ ▁References ▁ ▁Category : B - type ▁main - sequence ▁stars ▁Category : Shell ▁stars ▁Category : Lib ra ▁( const ell ation ) ▁Category : D urch m uster ung ▁objects ▁Lib ra e , ▁ 4 8 ▁ 1 4