Knowledge of the [Formula Presented] reaction rate is important for understanding stellar explosions, but it was uncertain because the properties of an expected but previously unobserved [Formula Presented] state in [Formula Presented] were not known. This state would provide a strong s-wave resonance for the [Formula Presented] system and, depending on its excitation energy, could dominate the stellar reaction rate at temperatures above 0.2 GK. We have observed this missing [Formula Presented] state by measuring the [Formula Presented] excitation function with a radioactive [Formula Presented] beam at the ORNL Holifield Radioactive Ion Beam Facility (HRIBF). We find that the state lies at a center-of-mass energy of [Formula Presented] keV [Formula Presented] and has a width of [Formula Presented] The measured properties of the resonance are only consistent with a [Formula Presented] assignment
