The 30P(p, γ)31S reaction in classical novae: progress and prospects

The unknown thermonuclear rate of the 30P(p, γ)31S reaction at classical-nova temperatures currently prohibits the accurate modeling of nova nucleosynthesis in the A ⩾ 30 region. This is hindering the calibration of nova thermometers based on observed O/S, S/Al, O/P, and P/Al abundance ratios in nova ejecta, the calibration of a meter to probe mixing at the core-envelope interface in novae based on the observed Si/H abundance ratio, and the identification of candidate pre-solar nova grains found in primitive meteorites based on laboratory measurements of their 30Si/28Si isotopic ratios. Each of these diagnostics could address key questions in our understanding of classical novae if the 30P(p, γ)31S rate were known. We review progress on the determination of the 30P(p, γ)31S rate leading to a critical assessment of current interpretations of published data and prospects for future work.