Betelgeuse has a companion star larger than the Sun but it's orbiting within Betelgeuse's extended atmosphere at 4AU.  Causes brightness variations.   #space #astronomy 
<br /><a href='https://www.skyatnightmagazine.com/news/betelgeuse-companion-star'>https://www.skyatnightmagazine.com/news/betelgeuse-companion-star</a>