ARCS AND FILAMENTS Lying in the Cygnus OB 3 association, WR 134 is responsible for this delicate arc captured by the Mayall 4-meter telescope at Kitt Peak National Observatory. During the WR phase, the fast stellar wind plows into the ambient medium, which may include matter previously shrugged off by the supergiant. When the high-speed winds collide with the nebula around the star, they generate shocks that we see as arcs in the visible. 30 AUGU S T 2 019 * SK Y & TELESCOPE T. A . RECTOR / UNIV ERSIT Y OF A L ASK A A NCHOR AG E / H. SCHWEIK ER / WIY N / NOAO / AUR A / NSF Wolf-Rayet Nebulae