Alert! Nova Cas 2021 mag 9

Alerts and Monitoring of Novae
John Coffin
Posts: 15
Joined: Tue Nov 27, 2018 5:43 pm

Re: Alert! Nova Cas 2021 mag 9

Post by John Coffin »

Hi everyone, here are some velocity plots from my Alpy spectrum from 22nd March.
nova cas velocity plot 2203_ balmer.png
nova cas velocity plot 2203_ balmer.png (26.01 KiB) Viewed 8692 times
nova cas velocity plot 2203.png
nova cas velocity plot 2203.png (32.96 KiB) Viewed 8692 times
The wavelength calibration of my Alpy normally becomes more inaccurate at shorter wavelengths, this is something two other Alpy users have noticed. The error causes a 2 Angstrom blue shift at H gamma.

Best wishes, John
Christian Buil
Posts: 1431
Joined: Mon Sep 26, 2011 6:59 pm
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Re: Alert! Nova Cas 2021 mag 9

Post by Christian Buil »

A spectrum for the 23-March-2021 taken by using a Star'Ex spectrograph (600 l/mm grating + 23 microns slit) on a 8-inch Newton telescope. The exposure is 12 x 300 seconds :

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A more contrasted display:

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The measured resolution is R=1700 and the SNR is 240 near 6400 A. Note the high efficiency of Star'Ex, here the result for a one-shot image of 300 exposure time only:

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But note the major limitation of Star'Ex (a 3D-printing spectrograph) - the acceptable spectral range is between 5400 and 7400 A for the actual version. For IR or UV, and a nearly similar spectral résolution, the solution is Alpy600, LISA,... or the powerful and very recent UVEX by Shelyak.

Christian Buil
Christian Buil
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Joined: Mon Sep 26, 2011 6:59 pm
Contact:

Re: Alert! Nova Cas 2021 mag 9

Post by Christian Buil »

New processing of Star'Ex spectrum for the 23 March (the near-IR 7065A He is now visible):

Image

Image


Christian Buil
Christian Buil
Posts: 1431
Joined: Mon Sep 26, 2011 6:59 pm
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Re: Alert! Nova Cas 2021 mag 9

Post by Christian Buil »

A near-IR spectrum (25-March-2021) - Pashen series is in emission:

Image

Christian Buil
HughAllen
Posts: 57
Joined: Mon Mar 23, 2015 7:17 pm
Location: The Mendip Hills, 15 miles south of Bath, UK

Alpy 600 spectra Nova Cas 2021: Mar 22 v Mar 24

Post by HughAllen »

A comparison of the nova spectrum on Monday and yesterday evenings with my Alpy 600 spectroscope. If the visual magnitudes are assumed to be similar on the two evenings then an increase in the Balmer emission is visible with a small decrease in the HeI emission
Cheers
Hugh
Nova Cas 2021 Mar 22 v Mar 24.png
Nova Cas 2021 Mar 22 v Mar 24.png (34.46 KiB) Viewed 8579 times
Hugh Allen
Alpy 600 user
Paolo Berardi
Posts: 578
Joined: Thu Sep 29, 2011 10:51 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Paolo Berardi »

Hi all,

I tried to observe the nova with a very strong atmospheric turbulence, especially for the second spectrum. Near-IR regions.

Image

Image

Clear sky!
Paolo
Paolo Berardi
Posts: 578
Joined: Thu Sep 29, 2011 10:51 pm

Re: Alert! Nova Cas 2021 mag 9

Post by Paolo Berardi »

Hi all,

new spectra for March 26.

Image

Image

A couple of cloudy nights are expected here... Hope it's better for you!

Paolo
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,

Very impressive spectra in the near infrared Paolo and Christian !!
Here is my update for the monitoring of the nova Cas 2021.
The following spectra were obtained with my Alpy 600, respectively, the 23th of March at 20 h 10 TU (resolution of 525, JJ = 2459297.3404) with an acquisition time of 36 min (12 x 180s) and the 24th of March at 19 h 55 TU (resolution of 529, JJ = 2459298.33) with an acquisition time of 18 min (6 x 180s) :
Nova Cas 2021 on March 23th, 2021
Nova Cas 2021 on March 23th, 2021
_novacas2021_20210323_840_Christophe Boussin_3600_7395.png (96.19 KiB) Viewed 8467 times
Nova Cas 2021 on March 24th, 2021
Nova Cas 2021 on March 24th, 2021
_novacas2021_20210324_830_Christophe Boussin_3600_7395.png (84 KiB) Viewed 8467 times
Nova Cas 2021 on March 20th, 23th and 24th 2021 (identification of some lines from PlotSpectra)
Nova Cas 2021 on March 20th, 23th and 24th 2021 (identification of some lines from PlotSpectra)
Clear skies,

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
Olivier GARDE
Posts: 1243
Joined: Thu Sep 29, 2011 6:35 am
Location: Rhône Alpes FRANCE
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Re: Alert! Nova Cas 2021 mag 9

Post by Olivier GARDE »

At this time, I'm on the nova with an eShel spectrograph.

Image
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Olivier GARDE
Posts: 1243
Joined: Thu Sep 29, 2011 6:35 am
Location: Rhône Alpes FRANCE
Contact:

Re: Alert! Nova Cas 2021 mag 9

Post by Olivier GARDE »

Evolution of the nova in 8 days taken with an eShel spectrograph (R=11000) and an RC400

H Alpha profil

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H beta profil

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Velocity of the Balmer's lines

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and the full spectrum cut at 4000 Å because the blue part is very noisy (many obstacles like trees)

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LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
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