Special DAWN Cake Talk - Pieter van Dokkum

Much of the baryonic universe resides in gas that is extraordinarily difficult to detect directly, from the cosmic web surrounding galaxies to faint structures in our own Galactic neighborhood. MOTHRA is a new wide-field imaging system designed to reach extremely low surface brightnesses in emission lines (Hα, [NII], and [OIII]). I will describe the motivation for MOTHRA and the instrument’s unusual design and construction. I will then present some of our first results, including new observations of the Helix Nebula that demonstrate MOTHRA’s ability to reveal faint, extended gas structures over very large angular scales.