Comet classification with new methods for gas and dust spectroscopy

► Presented gas and dust production rates of 26 comets from the Lick 3-m telescope. ► Developed a new extended source statistical long-slit sky subtraction method. ► Showed that C2 and C3 have different depletion patterns in Jupiter-family comets. ► Showed dust release early in coma formation, and Afρ was not constant in coma.