The beautiful comet C/2020 F3 NEOWISE was bright enough to be easy reachable with the Alpy600 spectrograph, but most of the time it was close to the horizon. Mid to end of July 2020 it was a compromize between getting higher over horizon and getting rapidly dimmer due to growing sun distance. Only one session was successful to record a spectrum, the second attempt two days later failed due to clouds passing by.
I took many images and one spectrum:
2020-07-20 Spectrum, the sky was clear with mediocre transparency and average seeing, at temperature of 21° C
Data about Comet C/2020 F3 NEOWISE
Position:
RA 09h 42m 10.00s, DEC +47° 10' 08.0" (at start time of spectroscopy session)
Discovery:
2020 March 03 by reactivated space telescope WISE (NEOWISE mission)
2020-07-20 22:27 - 22:51 CEST, Roof Observatory Kaufering,
Meade 14" ACF telescope on Taurus GM-60 mount, Astro Physics reducer CCDT67,
Alpy600 with guiding unit, CCD camera: Atik 428EX, guiding camera: ASI 120 MM; recording software: AstroArt, guiding software: PHD2;
Wavelength calibration: Hg lines from energy saving lamp and Ne lines from flicker flame light bulbs,
instrumental response calibration: with reference star HIP 53295, A1 VsSi, data reduction: with
Integrated Spectrographic InNovative Software from Christian Buil;
The spectrum consists mainly of bands from molecules. The strongest emission line in near UV at 3880 Å is from the Cyanogen radical (CN). Other lines are identified as diatomic carbon or Tricarbon forming swan bands and the Amino radical (NH2). The identification was done with help of literature, see [2] and [3]. Some days earlier a strong sodium line has been observed in low resolution spectra, see [4]. It seems, it has been vanished in my spectrum, the sodium line is rather small.
