Discovery of an Exceptionally Strong $\beta$-Decay Transition of $^{20}$F and Implications for the Fate of Intermediate-Mass Stars

Understand

A significant fraction of stars between 7-11 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, due to 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 have established that its strength is exceptionally large and enhances the capture rate by several orders of magnitude.