spectro-aras.com

Hello at all,

That is Nova Cas 2021 on the night 30 12 2021.

Have a nice New Year, J. Guarro.

Thanks Etienne for a very interesting link to ATel 15093. From the series of spectra that I have been capturing with my Alpy spectroscope I could see that the pair of emission lines, NIII 4638Å (Bowen blend with CIII) and He II 4686Å, made a first appearance in early August coincident with the nova fading to around mag 8.5, before disappearing as the nova re-brightened. The nebula line [N II] 5755Å also made a brief appearance:
The spectrum of this beautiful nova has been oscillating as much as its brightness!

Cheers
Hugh

Hello,

This is Nova Cas 2021 on first 2022 days.

Cheers, J. Guarro.

Hello,

That is another example of its movements.

Cheers, J. Guarro.

Hello,

This last January I have been observing Nova Cas 2021, almost every day from Piera and SMM observatories. The star has been changing its graphic overall on the blue region.

That picture shows its current state.

Regards, J. Guarro.

I recently brought together the 46 spectra that I captured 2021 March 22 - 2022 March 22 to paint a spectroscopic portrait of Nova Cas 2021. The results are described in a short paper in the Variable Star Section Circular no.192 just published by the British Astronomical Association, which can be downloaded as a pdf at https://britastro.org/vss/VSSC192.pdf
Here is a superposition of the spectra that is one of the figures from the paper:

This nova has been a hugely enjoyable spectroscopic project
Cheers
Hugh

Hi Hugh,

You did a really great job !!
Yes, this nova was really amazing to follow and... the story is not quite over !

I'm back with a new spectrum of the Nova Cas 2021 obtained the 19th of June at 0 h 40 TU (resolution of 542, JJ = 2459749.528) with my Alpy 600 and an acquisition time of 50 min (5 x 600s) :
As you indicate in your paper, I also wonder if the line at 5303 A is indeed that of [Fe XIV] ?

(Johnson V : green squares) According to the AAVSO website, the magnitude of the Nova is now close to 11 !!

Clear skies to all !!

Christophe BOUSSIN

Hi all,

With delay, here is a new spectrum of the Nova Cas 2021 obtained the 17th of September at 23 h 07 TU (resolution of 529, JJ = 2459840.4633) with my Alpy 600 and an acquisition time of 40 min (4 x 600s) :
I note a very clear evolution of the [Fe VII] lines at 5721 and 6087 A !

(Johnson V : green squares) According to the AAVSO website, the magnitude of the Nova is still below 12 : it's still an easy target but unfortunately for me, the weather looks like a parade of clouds !!
Will anyone have better luck?

Clear skies to all !!

Christophe BOUSSIN