Relating Hubble observations to the inside of a novae explosion: Several years ago, fluorine was observed in the spectrum of a nova explosion for the first time by a joint exercise between the Hubble Space Telescope and the Nordic Optical Telescope. This provides a powerful tool to compare astronomical observations with theoretical stellar models, because only one stable isotope of fluorine exists, 19F, and its quantity is extremely sensitive to the nuclear reactions that create and destroy it as well as the temperature & density conditions in the explosion. One such reaction, p (19Ne,γ)20Na, was measured for the first time at the DRAGON facility, using a beam of short-lived 19Ne produced at ISAC. This long sought-after reaction cross section was previously inaccessible to direct measurement. The results reduce the uncertainties resulting from nuclear physics inputs to negligible levels when comparing theoretical stellar models to the HST observations.