6533b7d6fe1ef96bd1266436

RESEARCH PRODUCT

Discovery of an Exceptionally Strong β -Decay Transition of F20 and Implications for the Fate of Intermediate-Mass Stars

D. F. StrömbergH. MöllerB. A. BrownS. T. OhlmannSamuel JonesSamuel JonesAri JokinenP. C. SrivastavaSami Rinta-antilaW. H. TrzaskaOliver S. KirsebomOliver S. KirsebomJouni SuhonenIain MooreFriedrich K. RöpkeFriedrich K. RöpkeGabriel Martínez-pinedoJoel KostensaloAnu KankainenTommi EronenK. RiisagerM. HukkanenH. O. U. FynboHeikki PenttiläKarlheinz LangankeAndrea IdiniJuha ÄYstö

subject

PhysicsSolar massThermonuclear fusionElectron captureDegenerate energy levelsGeneral Physics and AstronomyAstrophysics01 natural sciencesStarsNeutron starSupernovaOrders of magnitude (time)0103 physical sciencesAstrophysics::Solar and Stellar Astrophysics010306 general physics

description

A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. The answer depends critically on the rate of electron capture on ^{20}Ne in the degenerate oxygen-neon stellar core. However, because of the unknown strength of the transition between the ground states of ^{20}Ne and ^{20}F, it has not previously been possible to fully constrain the rate. By measuring the transition, we establish that its strength is exceptionally large and that it enhances the capture rate by several orders of magnitude. This has a decisive impact on the evolution of the core, increasing the likelihood that the star is (partially) disrupted by a thermonuclear explosion rather than collapsing to form a neutron star. Importantly, our measurement resolves the last remaining nuclear physics uncertainty in the final evolution of degenerate oxygen-neon stellar cores, allowing future studies to address the critical role of convection, which at present is poorly understood.

https://doi.org/10.1103/physrevlett.123.262701