Özet:
This project aims to determine the elemental abundances in the ejecta of some recent classical novae in the nebular phase. This is done using the comparison of the fluxed of emission lines in the spectra of classical novae ejecta to the fluxes of lines calculated using the photoionization code Cloudy. The chemical composition is of the shell is one of the main inputs of the code, then the code determines the fluxes of emission line (among other outputs). These calculated fluxes are compared to the observed fluxes and an iterative process can be performed to determine the elemental abundances in the nova.