Probable nova in Hercules mag 6.4 !

Alerts and Monitoring of Novae
Stephane Charbonnel
Posts: 70
Joined: Thu Sep 29, 2011 10:20 pm
Location: FR, 49 ou 44

Re: Probable nova in Hercules mag 6.4 !

Post by Stephane Charbonnel »

As David Boyd write it, it has completly changed from the day before !

It looks like a nova now but already fainter as 24H before.
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: Probable nova in Hercules mag 6.4 !

Post by Joan Guarro Flo »

Hello at all,

As David has said the Nova Her 2021 magnitude has decreased a lot and its aspect has changed.

You can see some graphic comparaisons here.

Cheers, J.Guarro.
Attachments
NOVA Her 2021a-1.jpg
NOVA Her 2021a-1.jpg (116.19 KiB) Viewed 5416 times
NOVA Her 2021a-2.jpg
NOVA Her 2021a-2.jpg (149.57 KiB) Viewed 5416 times
NOVA Her 2021a-3.jpg
NOVA Her 2021a-3.jpg (79.96 KiB) Viewed 5416 times
Olivier GARDE
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Location: Rhône Alpes FRANCE
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Re: Probable nova in Hercules mag 6.4 !

Post by Olivier GARDE »

I followed the nova during all the night and was able to see its evolution in 6 hours

The whole spectrum

Image

H Alpha evolution
Image

H Beta evolution
Image

H Gamma evolution
Image
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: Probable nova in Hercules mag 6.4 !

Post by Joan Guarro Flo »

Hello,

That is Nova Her2021 this last night, you can see here the good performance of NOU_T echelle with the ASI2600 MM camera.

Cheers, J.Guarro.
Attachments
Nova Her 2021 asi 1.jpg
Nova Her 2021 asi 1.jpg (87.35 KiB) Viewed 5359 times
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
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Re: Probable nova in Hercules mag 6.4 !

Post by Robin Leadbeater »

The shift in the H alpha, beta line profiles from blue to red while still centred on the rest wavelength is interesting.
https://britastro.org/specdb/data_graph ... &multi=yes
Increasing transparency might level the line profile but why are we now seeing more emission from the back of the system? Is this an orbital effect ?


Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
David Boyd
Posts: 161
Joined: Wed Dec 11, 2013 5:50 pm

Re: Probable nova in Hercules mag 6.4 !

Post by David Boyd »

The following plot shows the change in absolute flux of the nova over the last 4 days. These R~1000 spectra have been calibrated in absolute flux using concurrently recorded V magnitudes of 6.35, 8.38 and 9.77 respectively.

David
Nova Her 2021 12-13-15 June.png
Nova Her 2021 12-13-15 June.png (45.38 KiB) Viewed 5291 times
Daniel Dejean
Posts: 127
Joined: Sun Sep 18, 2016 7:20 am

Re: Probable nova in Hercules mag 6.4 !

Post by Daniel Dejean »

Modeste contribution lors du test d’une configuration volontairement dégradée d’un Alpy avec une fente de 35microns et une caméra Atik428EX en bin2x2. La résolution obtenue n’est que d’environ 380 mais peut-être intéressante dans certaines situations : raies larges et faible luminosité (ce n’est pas encore le cas ici).
Pour le fun, le graphique a été tracé avec un script Python écrit après les excellentes sessions de Shelyak. Merci encore pour ces formations.

Image

Malgré la faible définition de cette observation il semble possible d'évaluer les vitesses d'expansion de l'ordre de 2600km/s au 15/06. Elle paraît légèrement supérieure en Halpha.

Image
Last edited by Daniel Dejean on Fri Jun 18, 2021 5:52 pm, edited 1 time in total.
Christophe Boussin
Posts: 170
Joined: Sun Aug 21, 2016 6:04 pm

Re: Probable nova in Hercules mag 6.4 !

Post by Christophe Boussin »

Hello all,

As other observers have noted, the spectrum of Nova Her 2021 is changing very fast !
In particular, the evolution of the Halpha line is already clearly visible at low resolution with a modification of the overall shape of the top of the profile.

I obtained two spectra of the Halpha line of Nova Her 2021 at high resolution on June 14 at 22 h 39 TU (resolution of 18220, JJ = 2459380.4435) and on June 15 at 22 h 43 TU (resolution of 18835, JJ = 2459381.4463) with my LHIRES III (grating of 2400 lines / mm, acquisition time of 60 min for each spectrum (6 x 600s)).
Halpha line of Nova Her 2021 on June 14th and 15th 2021
Halpha line of Nova Her 2021 on June 14th and 15th 2021
novaher2021_Halpha_Christophe Boussin.png (45.77 KiB) Viewed 5243 times
What is most noticeable is the width of the Halpha line but we can also note the evolution in detail of its profile in one day (especially around +1000 km/s) !

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

Re: Probable nova in Hercules mag 6.4 !

Post by Paolo Berardi »

Hi all, great spectra! My contribution with some observations in near-IR interval, using Lhires III with 830 l/mm NIR blazed grating.

The different evolution of neutral oxygen lines, O I 7772 and O I 8446, from june 13 to June 16 (Lyman-beta pumping?)

Image

I hope to keep observing our interesting subject (but its brightness decreases)...

Clear sky!
Paolo
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
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Re: Probable nova in Hercules mag 6.4 !

Post by Robin Leadbeater »

Does anyone have an identification of the strong P Cygni line in early spectra at ~6380 emission/6295 absorption see here for example ?
http://www.spectro-aras.com/forum/viewt ... 785#p15737

Thanks
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
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