The C₆₀:C₆₀⁺ ratio in diffuse and translucent interstellar clouds

Context. Insight into the conditions that drive physics and chemistry in interstellar clouds is gained from determining abundance charge state of their components. Aims. We propose an evaluation C60:C60+ ratio diffuse translucent exploits electronic absorption bands so as not to rely on ambiguous IR emission measurements. Methods. The determined by analyzing archival spectra literature data. Information cation population obtained published characteristics main attributed C60+ cross sections already reported for vibronic cation. neutral molecules described terms upper limit because relevant C60 are brought out observations. revise oscillator strengths measure spectrum molecule isolated Ne ice complete them. Results. scale down find approximately 1.3 ratio. Conclusions. conclude fraction buckminsterfullerene may be notable despite non-detection expected bands. More certainty will require improved laboratory data