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The $^{22}$Ne(p,$\gamma$)$^{23}$Na reaction is the most uncertain process inthe neon-sodium cycle of hydrogen burning. At temperatures relevant fornucleosynthesis in asymptotic giant branch stars and classical novae, itsuncertainty is mainly due to a large number of predicted but hithertounobserved resonances at low energy. Purpose: A new direct study of low energy$^{22}$Ne(p,$\gamma$)$^{23}$Na resonances has been performed at the Laboratoryfor Underground Nuclear Astrophysics (LUNA), in the Gran Sasso NationalLaboratory, Italy. Method: The proton capture on $^{22}$Ne was investigated indirect kinematics, delivering an intense proton beam to a $^{22}$Ne gas target.$\gamma$ rays were detected with two high-purity germanium detectors enclosedin a copper and lead shielding suppressing environmental radioactivity.Results: Three resonances at 156.2 keV ($\omega\gamma$ =(1.48\,$\pm$\,0.10)\,$\cdot$\,10$^{-7}$ eV), 189.5 keV ($\omega\gamma$ =(1.87\,$\pm$\,0.06)\,$\cdot$\,10$^{-6}$ eV) and 259.7 keV ($\omega\gamma$ =(6.89\,$\pm$\,0.16)\,$\cdot$\,10$^{-6}$ eV) proton beam energy, respectively,have been observed for the first time. For the levels at 8943.5, 8975.3, and9042.4 keV excitation energy corresponding to the new resonances, the$\gamma$-decay branching ratios have been precisely measured. Three additional,tentative resonances at 71, 105 and 215 keV proton beam energy, respectively,were not observed here. For the strengths of these resonances, experimentalupper limits have been derived that are significantly more stringent than theupper limits reported in the literature. Conclusions: Based on the presentexperimental data and also previous literature data, an updated thermonuclearreaction rate is provided in tabular and parametric form. The new reaction rateis significantly higher than previous evaluations at temperatures of 0.08-0.3GK.

Direct measurement of low-energy $^{22}$Ne(p,$\gamma$)$^{23}$Na resonances