We report on the observation of a new resonance at $E_R^{\mathrm{l}\mathrm{a}\mathrm{b}}=190\mathrm{k}\mathrm{e}\mathrm{V}$ in the ${}^{17}\mathrm{O}(p,\gamma ){}^{18}\mathrm{F}$ reaction. The measured resonance strength amounts to $\omega {\gamma }_{p\gamma }=(1.2\pm 0.2)\times {10}^{-6}\mathrm{e}\mathrm{V}$. With this new value, the uncertainties in the ${}^{17}\mathrm{O}(p,\gamma ){}^{18}\mathrm{F}$ and ${}^{17}\mathrm{O}(p,\alpha ){}^{14}\mathrm{N}$ thermonuclear reaction rates are reduced by orders of magnitude at nova temperatures. Our significantly improved reaction rates have major implications for the galactic synthesis of ${}^{17}\mathrm{O}$, the stellar production of the radioisotope ${}^{18}\mathrm{F}$, and the predicted oxygen isotopic ratios in nova ejecta.

• Received 30 April 2004

DOI:https://doi.org/10.1103/PhysRevLett.93.081102