spectro-aras.com

v694mon_20211212_259_Jim Leyvswoody.png Things have changed... Hα has two peaks now v694mon_20211212_259_Jim Leyhalphavswoody.png Compared to my reference star v694mon_20211212_259_Jim Leyvelocity.png But Fe II lines and Balmer lines are shifted to the blue v694mon_20211212_259_Jim Leybluezoom.png ...

Thank you for that wonderful explanation François.
I had a hard time understanding the definition of critical density given by Osterbrock and Ferland. For me, their definition was more opaque than this optically thick nova.

After re-reading Osterbrock page 109, the longer lifetime of the 1D term could result in selectively more collisional de-excitation, thus weakening the 6583 and 6548 lines.

Perhaps both density and electron temperature are important in this situation.

Good question François, Is it because the electron temperature is still too high? The 5755 line is produced by transition from a higher energy ¹S level than the ¹D level that produces the 6583 and 6548 lines. So if the electron temperature is still very high, the higher level (¹S) would be much more...

Salut Etienne, Mon 290 MM ne m'a jamais déçu. Mais ça pourrait être trop petit avec le C11. Pour vous donner une idée du champ de vision avec mon Alpy 600, voici une image prise de PhD de la nébuleuse d'orion. Newtonian de 200 mm f/4, 800 mm avec une fente de 10 µm. orion.jpg J'ai aussi le 178 MM, m...

Salut Francois,
J'ai pris ce spectrum de V694 Mon hier soir.
Pensez-vous qu'il vous serait utile? Je n'ai pas beaucoup de confiance dans mon spectro...

Thanks for your explanations François.
Are those not emissions for NIII at 4638 and HeII at 4686? Since the ionization potentials for N, N+ and He are all greater than for O, does one expect to see [OI]?

Pas beaucoup de changement mais ça coule plus vite.

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) novaper...

Reassuringly, I seem to be getting the about the same results as people with far more skill than myself. novaperseus2020_20201206_209_and1202_083.png 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 ...