Follow-Up Spectroscopy of Comet C/2020 F3

We have carried out follow-up spectroscopic observations of comet C/2020 F3 with the Échelle spectrograph FLECHAS, which is operated at the 90cm telescope of the University Observatory Jena. The comet was observed on 21, 23, 29, 30, and 31 July 2020. In the first three observing epochs we used the 1x1 binning mode of FLECHAS (R~9300) and three spectra each with an integration time of 150s were taken (300s on 29 July 2020). Due to the dimming of C/2020 F3 of about two magnitudes between the first and last observing epoch, on 30, and 31 July 2020 we observed the comet with the 2x2 binning mode of the instrument (R~7400) and three spectra of the comet each with an integration time of 300s were taken. All fully reduced spectra are available online for download. In the wavelength range between 4500 and 7500Å the spectrum of comet C/2020 F3 shows many emission lines the most prominent ones are those of C2, NH2, and [OI], which are all present in the spectrum of the comet in all observing epochs. In contrast, strong sodium emission (Na doublet) is detected on 21 July 2020, which significantly weakens until 23 July 2020 and is not detected anymore in the spectrum of the comet on 29 July 2020.