spectro-aras.com

To add to what David's plot shows, here is a plot over the same time period that show the evolution of Halpha in velocity.
And for the same dataset note the appearance and interesting evolution of the Fe Multiplet (4924, 5018, 5169)Å. Nice to have two Novae in the northern sky (the other being Nova Cas 2020 even though it is currently at about mag 13.6) to observe at the same time and both exhibiting visible changes at low resolution on a daily basis.

Woody

Reassuringly, I seem to be getting the about the same results as people with far more skill than myself.
I think there is some evidence for Ca II K & H emission, consistent with earlier spectra in IR.

I think there is also some suggestion of [O I] at 630.0 nm and 636.4 nm, again consistent with the IR spectra.

When I compare the Balmer lines, it looks to me like the absorption has roughly the same velocity for all lines. The emission lines get wider (hotter environment) with shorter wavelength. Why is the absorption component similar? I'm trying to understand the different contributions to the emission lines from fluorescence (pumping by Lyman-ß etc. when the iron curtain is lifted) and recombination. The rise of Hα emission seems to me that it might include the former and the rise of Ca II H & K emission to be an indication of the latter. Any ideas?

This paper https://arxiv.org/pdf/2010.07481.pdf
EARLY SPECTRAL EVOLUTION OF CLASSICAL NOVAE: CONSISTENT EVIDENCE FOR MULTIPLE DISTINCT OUTFLOWS

predicts a slow wind < 1000 km/s before maximum light and a fast wind > 1000 km/s after maximum light.

This might be what we are seeing (here is Hß) Notice the blue absorption below 1000 km/s before 12/06 and the absorption around 1500 km/s observed on 12/06.

Has the nova reached its optical peak?

Update of the lightcurve and ARAS spectra.
V723 Cas (Nova Cas 1995) for comparison
And a classical nova Nova Del 2013 (old friend of ARAS observers)

Bonsoir à tous, placé une nouvelle contribution à l'observation de cette nova.
Umberto

Congratulazione Umberto !

Very nice spectra in the infrared.

Un abbraccio, Joan.

Pas beaucoup de changement mais ça coule plus vite.

Nice work Jim! I am seeing the same trend tonight in my spectra. I measured the V mag at 9.26. Here are my last two flux calibrated spectra.

Woody

Bonsoir à tous, voici le profil d'observation du 12-12-2020. Cette fois, moi aussi, comme Paolo Berardi, j'ai utilisé un filtre rouge pour éliminer la pollution de second ordre.
J'attache une comparaison entre le profil sans filtre et celui avec filtre où il est montré que l'ordre 2 dans l'IR pollue le spectre d'ordre 1.
Umberto.
Comparison