Experimental Study of 17O(p,α)14N and 17O(p,γ)18F for Classical Nova Nucleosynthesis

We investigated the proton‐capture reactions on 17O occuring in classical nova explosions. We observed a previously undiscovered resonance at ERlab=194.1±0.6 keV in the 17O(p,α)14N reaction, with a measured resonance strength ωγpα=1.6±0.2 meV. We studied in the same experiment the 17O(p,γ)18F reaction by an activation method and the resonance‐strength ratio was found to be ωγpα/ωγpγ=470±50. The corresponding excitation energy in the 18F compound nucleus was determined to be 5789.8±0.3 keV by γ‐ray measurements using the 14N(α,γ)18F reaction. These new resonance properties have important consequences for 17O nucleosynthesis and γ‐ray astronomy of classical novae.