Alert! Nova Cas 2021 mag 9

[Robin Leadbeater]

From:
https://britastro.org/node/2581


Yuji Nakamura (Kameyama, Mie, Japan) has reported the discovery of a possible nova, PNV J23244760+6111140, on March 18.4236

Tonny Vanmunster confirmed the transient later that day at V = 8.95 +/- 0.03 (CBA Extremadura Observatory using a 0.40-m f/5.1 telescope and SX-46 CCD camera)

ATel #14471 reports spectroscopic classification of the object as a classical nova (Hiroyuki Maehara (National Astronomical Observatory of Japan), Kenta Taguchi (Kyoto University), Yusuke Tampo (Kyoto University), Naoto Kojiguchi (Kyoto University), Keisuke Isogai (Kyoto University).

Nova Cas 2021 is at RA 23 24 47.73 Dec +61 11 14.8 (J2000.0)

[Francois Teyssier]

Thank you Patrick, Robin, for the alert.

The page is ready for the spectra.
Probably the last one in the old database format before the tranfer of novae section to the new online database.
http://www.astrosurf.com/aras/Aras_DataBase/Novae/2021_NovaCas2021.htm

Please use "Nova Cas 2021" as OBJNAME.

I wish you clear skies.
Blue sky here ...

François Teyssier

[David Boyd]

This spectrum of Nova Cas 2021 was recorded with a LISA spectrograph on a C11 during a short break in generally overcast skies tonight. It shows strong emission lines of the hydrogen Balmer series and He I. There are P Cygni profiles extending to around -2500 km/s relative to the rest wavelength on all emission lines. The spectrum was calibrated in absolute flux using currently recorded B and V photometry which gave V = 7.77+-0.04 and B-V = 0.50.

David

Nova Cas 2021 19 Mar 21.png (31.1 KiB) Viewed 2196 times

[Francois Teyssier]

Hi David,
Well done!



François

[Pascal Le Du]

Hello

My small contribution for this very interesting Nova.
Spectrum realized from the tip of Brittany with a 200 mm newton and an Alpy600 (7x30sec).

Fente sur cible

FenteNovaCas2021.jpg (161.28 KiB) Viewed 2137 times

NovaCas2021.jpg (44.47 KiB) Viewed 2142 times

For information, it is better to make the spectrum of this nova with a vertical slit.
Indeed, as we can see on the PanSTARRS image and on my spectrum which compiles 29 exposures of 30 seconds, the stars located near the nova can pollute its spectrum.

PanSTARRS DR2

NovaCas2021_PanSTARRS_DR1.jpg (130.83 KiB) Viewed 2117 times

NovaCas2021 29x30 sec

NovaCas2021_29x30sec.jpg (34.63 KiB) Viewed 2117 times

Pascal

[Matthieu Le Lain]

Hi all,

A new spectrum of NovaCas2021 with an Alpy600 last night, on C8 f/6.3 - Atik460Ex - 10 x 90s exp.

NovaCas2021_20210320015823_lines.png (42.34 KiB) Viewed 2077 times

Matthieu

[Olivier GARDE]

And my contribution with this spectrum taken with an eshel spectrograph (R=11000) with difficulty because I had a tree that was in the line of the sight of the nova !!! and very low in my north west horizon), so only 6 exposures of 600s each.

Here's the full spectrum (I cut the spectrum at 4300 Å because the blue part is very noisy).



And the quick calculation of the ejecta velocity on H Alpha and H beta line




The Helium I 5875 emission line, always with p Cyg profil

[Christophe Boussin]

Hello all,

Here is my contribution to the monitoring of the nova Cas 2021.
The following spectrum was obtained the 20th of March at 19 h 42 TU with my Alpy 600 (resolution of 528, JJ = 2459294.3211) and an acquisition time of 25 min (5 x 300s) :

Guiding camera field

Champ NOVA CAS 2021.png (183.43 KiB) Viewed 1990 times

Nova Cas 2021 on March 20th, 2021

_novacas2021_20210320_821_Christophe Boussin_3550_7400.png (99.45 KiB) Viewed 1990 times

Nova Cas 2021 on March 20th, 2021 (identification of some lines from PlotSpectra)

Clear skies,

Christophe BOUSSIN

[Joan Guarro Flo]

Hello at all,

This is Nova Cas 2021 last night from RSMM.

Cheers, J. Guarro.

[Francois Teyssier]

Excellent team!

Light curve (BVR) from AAVSO: