Alert! Nova Cas 2021 mag 9

Alerts and Monitoring of Novae
Christophe Boussin
Posts: 170
Joined: Sun Aug 21, 2016 6:04 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Christophe Boussin »

Hello all,

Here is a small update with one more spectrum before still several days of rain...
The spectrum was obtained July 12 at 0 h 10 TU (resolution of 18875, JJ = 2459407.5071) with my LHIRES III (grating of 2400 lines / mm, acquisition time of 60 min for each spectrum (6 x 600s)) and the comparison with the previous three ones.
Halpha line of Nova Cas 2021 on July 1st, 7th and 12th 2021
Halpha line of Nova Cas 2021 on July 1st, 7th and 12th 2021
novacas2021_Halpha_Christophe Boussin.png (31.12 KiB) Viewed 7390 times
The "blue" part of the Halpha line continues to evolve :
Halpha line of Nova Cas 2021 on July 1st, 7th and 12th 2021 (zoom)
Halpha line of Nova Cas 2021 on July 1st, 7th and 12th 2021 (zoom)
novacas2021_Halpha_zoom_Christophe Boussin.png (32.73 KiB) Viewed 7390 times
Clear skies to all !!

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan + Mewlon 180 F/12 / LHIRES III 2400 / Atik 460EX / Atik 314 L+) @ ARAS database
Matthieu Le Lain
Posts: 24
Joined: Mon Apr 15, 2019 4:33 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Matthieu Le Lain »

Hi all,

Here is a new spectrum of Nova Cas 2021 last night, with an Alpy600, 1800s (20x90s)
NovaCas2021_20210720T232010_base_mla.png
Matthieu
Christophe Boussin
Posts: 170
Joined: Sun Aug 21, 2016 6:04 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Christophe Boussin »

Hello all,

Nice spectrum Matthieu, the P Cygni profile is always well visible on the Balmer lines !
Here is my new comparison between my three last spectra of the Halpha line of Nova Cas 2021 at high resolution on July 16 at 22 h 06 TU (resolution of 18731, JJ = 2459412.4209), on July 28 at 22 h 52 TU (resolution of 19001, JJ = 2459424.453) and on July 29 at 23 h 28 TU (resolution of 18577, JJ = 2459425.4778) with my LHIRES III (grating of 2400 lines / mm, acquisition time of 60 min for each spectrum (6 x 600s)) and the previous one obtained on July 12.
Halpha line of Nova Cas 2021 on July 12th, 16th, 28th and 29th 2021
Halpha line of Nova Cas 2021 on July 12th, 16th, 28th and 29th 2021
novacas2021_Halpha_Christophe Boussin.png (36.36 KiB) Viewed 7112 times
Since July 16, the shape of the Halpha line profile in the "blue" part has evolved very clearly :
Halpha line of Nova Cas 2021 on July 12th, 16th, 28th and 29th 2021 (zoom)
Halpha line of Nova Cas 2021 on July 12th, 16th, 28th and 29th 2021 (zoom)
novacas2021_Halpha_zoom_Christophe Boussin.png (32.3 KiB) Viewed 7112 times
According to the AAVSO website, the brightness of the Nova increased by about 2.5 magnitudes (Johnson V) between July 11 and 26. Since then, it has decreased again by about 1.5 magnitude.

(Johnson V : green squares)
Light curve of the Nova CAS 2021 (AAVSO)
Light curve of the Nova CAS 2021 (AAVSO)
Clear skies to all !!

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan + Mewlon 180 F/12 / LHIRES III 2400 / Atik 460EX / Atik 314 L+) @ ARAS database
David Boyd
Posts: 161
Joined: Wed Dec 11, 2013 5:50 pm

Re: Alert! Nova Cas 2021 mag 9

Post by David Boyd »

Here is a spectrum of Nova Cas 2021 taken on 6th August with a LISA (R~1065) and calibrated in absolute flux using a concurrently measured V magnitude of 7.70. There are broad emission lines of H I Balmer and He I, all with P-Cygni absorption dips. The Balmer emission lines have FWHM ranging from 1400 km/s at H-alpha to 1790 km/s at H-delta and FWZI from 2000 km/s at H-alpha to 2300 km/s at H-delta. P-Cygni absorption dips are at -1200 km/s in the Balmer lines and at -1400 km/s in the He I lines. Note the Na I absorption lines on the edge of the He I 5876A line. Fe II emission lines are relatively weak but also broad and have double peaks at -150 km/s and +350 km/s.

David
novacas2021_20210806_882_D_Boyd.png
novacas2021_20210806_882_D_Boyd.png (30.86 KiB) Viewed 6854 times
Nova Cas 2021 6 Aug H I emission lines.png
Nova Cas 2021 6 Aug H I emission lines.png (29.44 KiB) Viewed 6854 times
Nova Cas 2021 6 Aug He I emission lines.png
Nova Cas 2021 6 Aug He I emission lines.png (37.12 KiB) Viewed 6854 times
Nova Cas 2021 6 Aug Fe II emission lines.png
Nova Cas 2021 6 Aug Fe II emission lines.png (18.52 KiB) Viewed 6854 times
Dubreuil Pierre
Posts: 202
Joined: Sat Oct 01, 2011 12:34 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Dubreuil Pierre »

Bonsoir

Hier soir avec UVEX(4) motorisé reseau, G600 750nm sur SC8

Dans le proche UV
Nova UV
Nova UV
Nova Cas_2021 UV.png (9.06 KiB) Viewed 6831 times
Dans le proche IR (avec filtre d'ordre)
Nova IR
Nova IR
Nova Cas 2021 IR.png (10.33 KiB) Viewed 6831 times
Nova extrêmement brillante .

Pierre
Christophe Boussin
Posts: 170
Joined: Sun Aug 21, 2016 6:04 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Christophe Boussin »

Hello all,

Here is my new comparison between my four last spectra of the Halpha line of Nova Cas 2021 at high resolution on August 1st at 1 h 20 TU (resolution of 18775, JJ = 2459427.5557), on August 8 at 1 h 37 TU (resolution of 18785, JJ = 2459434.5672), on August 12 at 0 h 30 TU (resolution of 18636, JJ = 2459438.5209), and on August 13 at 3 h 00 TU (resolution of 18396, JJ = 2459439.6251), obtained with my LHIRES III (grating of 2400 lines / mm, acquisition time of 60 min for each spectrum (6 x 600s) except the last one (4 x 600)) and the previous ones.

Since August 1, the Halpha line profile has undergone many striking changes. In particular with the emergence of a peak around + 390 km/s between August 1 and 8.
Halpha line of Nova Cas 2021 on July 16th, 28th, 29th and on August 1st, 8th, 12th and 13th 2021
Halpha line of Nova Cas 2021 on July 16th, 28th, 29th and on August 1st, 8th, 12th and 13th 2021
novacas2021_Halpha_Christophe Boussin.png (50.48 KiB) Viewed 6630 times
Halpha line of Nova Cas 2021 on July 16th, 28th, 29th and on August 1st, 8th, 12th and 13th 2021 (zoom)
Halpha line of Nova Cas 2021 on July 16th, 28th, 29th and on August 1st, 8th, 12th and 13th 2021 (zoom)
novacas2021_Halpha_zoom_Christophe Boussin.png (56.81 KiB) Viewed 6630 times
(Johnson V : green squares)
Light curve of the Nova CAS 2021 (AAVSO)
Light curve of the Nova CAS 2021 (AAVSO)
Clear skies to all !!

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan + Mewlon 180 F/12 / LHIRES III 2400 / Atik 460EX / Atik 314 L+) @ ARAS database
Christophe Boussin
Posts: 170
Joined: Sun Aug 21, 2016 6:04 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Christophe Boussin »

Hello all,

Here is my new comparison between my three last spectra of the Halpha line of Nova Cas 2021 at high resolution on August 21 at 0 h 06 TU (resolution of 18050, JJ = 2459447.5045, 8 x 600s), on August 25 at 0 h 35 TU (resolution of 17672, JJ = 2459451.5241, 7 x 600s) and at 23 h 33 TU (resolution of 17828, JJ = 2459452.4813, 6 x 600s), obtained with my LHIRES III (grating of 2400 lines / mm) and the previous ones in August.

The peak still visible in the Halpha line profile on August 13 disappeared between August 13 and 21 :
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th and 25th 2021
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th and 25th 2021
novacas2021_20210825_981_Christophe Boussin.png (50.79 KiB) Viewed 6259 times
The "blue" part also underwent new modifications between these 2 dates but the overall shape of this part is almost unchanged since the 21 :
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th and 25th 2021 (zoom)
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th and 25th 2021 (zoom)
novacas2021_20210825_981_zoom_Christophe Boussin.png (58.55 KiB) Viewed 6259 times
(Johnson V : green squares)
Light curve of the Nova CAS 2021 (AAVSO)
Light curve of the Nova CAS 2021 (AAVSO)
Clear skies to all !!

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan + Mewlon 180 F/12 / LHIRES III 2400 / Atik 460EX / Atik 314 L+) @ ARAS database
Matthieu Le Lain
Posts: 24
Joined: Mon Apr 15, 2019 4:33 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Matthieu Le Lain »

Hi all

congrats for your rigorous and close monitoring Christophe, it's very interesting so see the evolution.

Here is my new spectrum of Nova Cas 2021 with an alpy600
Nova Cas 2021 - ALpy600
Nova Cas 2021 - ALpy600
Matthieu
Christophe Boussin
Posts: 170
Joined: Sun Aug 21, 2016 6:04 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Christophe Boussin »

Hello all,

Thank you Matthieu !

Have you looked at your spectrum in detail ?
There are details that I think are interesting to identify...

Comparing your spectrum with other spectra in the ARAS database obtained before and after 26 August by other observers, I cannot find these details...
I wonder about these details in your spectrum...Some of these seem to be attributable to real lines !
In addition, on this date, the AAVSO's Nova Cas 2021 light curve shows a very clear decrease in brightness !

Is there a link?
Did other observers get a spectrum of the Nova Cas 2021 on the same date, 26 August ?

For my part, I continue to follow the Nova Cas 2021 with a new comparison between my last spectrum of the Halpha line of Nova Cas 2021 at high resolution on August 27 at 22 h 15 TU (resolution of 16625, JJ = 2459454.427, 8 x 600s) obtained with my LHIRES III (grating of 2400 lines / mm) and the previous ones in August.
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th, 25th and 27th 2021
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th, 25th and 27th 2021
novacas2021_20210827_Christophe Boussin.png (54.41 KiB) Viewed 6099 times
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th, 25th and 27th 2021 (zoom)
Halpha line of Nova Cas 2021 on August 1st, 8th, 12th, 13th, 21th, 25th and 27th 2021 (zoom)
novacas2021_20210827_zoom_Christophe Boussin.png (66.24 KiB) Viewed 6099 times
Clear skies to all !!

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan + Mewlon 180 F/12 / LHIRES III 2400 / Atik 460EX / Atik 314 L+) @ ARAS database
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Joan Guarro Flo »

Hello,

As you can see on excellent precedent observations by Christopher Bousin, David Boyd and others, I show here this interesting doble P Cyg effect.

Regards, J. Guarro.
Attachments
NOVA Cas 2021.png
NOVA Cas 2021.png (17.79 KiB) Viewed 6076 times
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