A. KARAKAS

The 22Ne(p,γ)23Na reaction, part of the neon-sodium cycle of hydrogen burning, may explain the observed anticorrelation between sodium and oxygen abundances in globular cluster stars. Its rate is controlled by a number of low-energy resonances and a slowly varying nonresonant component. Three new resonances at Ep = 156.2, 189.5, and 259.7 keV...

Background: Among the several inhomogeneities in the composition of globular cluster stars, an overabundance of 23Na is interpreted as the signature of the operation of the neon-sodium (NeNa) cycle. One of the hypothesis to explain the observed O-Na anticorrelation invokes massive asymptotic giant branch stars as the main agents. At...