Alert! Nova Cas 2021 mag 9

Alerts and Monitoring of Novae

Re: Alert! Nova Cas 2021 mag 9

Postby John Coffin » Tue Mar 23, 2021 7:06 am

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 2114 times


nova cas velocity plot 2203.png
nova cas velocity plot 2203.png (32.96 KiB) Viewed 2114 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
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Re: Alert! Nova Cas 2021 mag 9

Postby Christian Buil » Tue Mar 23, 2021 3:11 pm

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 :

Image

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:

Image

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
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Re: Alert! Nova Cas 2021 mag 9

Postby Christian Buil » Tue Mar 23, 2021 11:50 pm

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

Image

Image


Christian Buil
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Re: Alert! Nova Cas 2021 mag 9

Postby Christian Buil » Thu Mar 25, 2021 4:11 am

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

Image

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

Postby HughAllen » Thu Mar 25, 2021 12:56 pm

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 2001 times
Hugh Allen
Alpy 600 user
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Re: Alert! Nova Cas 2021 mag 9

Postby Paolo Berardi » Fri Mar 26, 2021 10:31 am

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
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Re: Alert! Nova Cas 2021 mag 9

Postby Paolo Berardi » Sat Mar 27, 2021 2:21 pm

Hi all,

new spectra for March 26.

Image

Image

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

Paolo
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Re: Alert! Nova Cas 2021 mag 9

Postby Christophe Boussin » Sat Mar 27, 2021 6:41 pm

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) :

_novacas2021_20210323_840_Christophe Boussin_3600_7395.png
Nova Cas 2021 on March 23th, 2021
_novacas2021_20210323_840_Christophe Boussin_3600_7395.png (96.19 KiB) Viewed 1889 times

_novacas2021_20210324_830_Christophe Boussin_3600_7395.png
Nova Cas 2021 on March 24th, 2021
_novacas2021_20210324_830_Christophe Boussin_3600_7395.png (84 KiB) Viewed 1889 times

novacas2021_20210324_830_Christophe Boussin.png
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
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Re: Alert! Nova Cas 2021 mag 9

Postby Olivier GARDE » Sun Mar 28, 2021 4:27 am

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
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Re: Alert! Nova Cas 2021 mag 9

Postby Olivier GARDE » Sun Mar 28, 2021 11:00 am

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)

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