Events at Physics
Abstract: I describe the discovery of a faint (1 Rayleigh) thirty-degree circular arc of ionized gas centered on the handle of the Big Dipper: the Ursa Major Arc. The arc subtends one radian of a circle of angular diameter 60 degrees, is detected in both H-alpha and diffuse ultraviolet emission and is one of the most unusual objects in the sky. I compare this object to other recently discovered large angular size supernova remnants and describe the significance of these objects. If time allows, I will share some other recent discoveries of ionized gas structures in the Milky Way.