Origin and occurrence of fluorine supernovae, atoms of neon could be hit by neutrinos during the explosion and converted to fluorine. In Wolf-Rayet stars (blue stars over 40 times heavier than the Sun), a strong solar wind could blow the fluorine out of the star before hydrogen or helium could destroy it. Finally, in asymptotic giant branch (a type of red giant) stars, fusion reactions occur in pulses and convection could lift fluorine out of the inner star. Only the red giant hypothesis has supporting evidence from observations. In space, fluorine commonly combines with hydrogen to form hydrogen fluoride. (This compound has been suggested as
Red Spider Nebula complex way. The central white dwarf, the remaining compact core of the original star, produces a powerful and hot (≈10,000 K) wind blowing with a speed of 300 kilometers per second, which has generated waves 100 billion kilometres high. The waves are generated by supersonic shocks formed when the local gas is compressed and heated in front of the rapidly expanding lobes. Atoms caught in the shocks radiate a visible light. These winds are what give this nebula its unique 'spider' shape and also contribute to the expansion of the nebula. The star at the center of the Red Spider