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Re: Nova Cep 2013

Posted: Sat Feb 09, 2013 9:28 pm
by Francois Teyssier
Hi Robin,

Nice spectrum

74 is the number of a Fe II multiplet (Grotrian diagram) with lengthwaves = 6148, 6247 and 6417 angströms
Another noticeable multiplet in Fe Nova spectra is (42) : 4924, 5018, 5169 angströms

See : http://www.astronomie-amateur.fr/Projet ... Novae.html
(bottom of the page) with a list of common lines in novae spectra

Bonne continuation

François

Re: Nova Cep 2013

Posted: Mon Feb 11, 2013 12:03 am
by Paolo Berardi
Your and my last observation clearly show a strong increase of h-alpha line intensity. I set my spectra with the profile scaling range 6650-6750 A (before I used 6600-6620, not a good range because of some h-alpha signal inside).

In my last spectrum (some hours ago) the h-alpha line has evolved showing a pronunced p-cygni absorption blueshifted (6545.4 A w/helio) at about 800 Km/s.

Spectrum of 10.747 feb 2013:

Image

Fit profile:

http://quasar.teoth.it/html/spectra/_no ... 10_747.fit

Comparison between 4, 6 and 10 february in h-alpha region:

Image

Robin, the SA100 spectrum looks very nice, sharp with plenty of spectral features (despite the optical collimation problems). Should 2nd order contamination be a minor problem because of reddened star? The first relatively strong signal is h-beta emission that impacts at about 9600 A. I see several emissions at 7800 and 8500 A (may be there are other emissions I do not see in the background of jpg image).

François, if you wish, take the profile in fit format for the ARAS page.

Ciao
Paolo

Re: Nova Cep 2013

Posted: Mon Feb 11, 2013 6:55 pm
by Francois Teyssier
Oh yes I wish, Paolo !

This is excellent. You have clearly the evolution of the different absorption systems (pre-maximum and principal, i think)
I updated the log with your spectrum and also main page with the evolution of H alpha line.

http://www.astrosurf.com/aras/novae/Nova2013Cep.html

Also two spectra sent by Jim from Florida.

Amitiés

François

Re: Nova Cep 2013

Posted: Wed Feb 13, 2013 4:26 pm
by Robin Leadbeater
Paolo Berardi wrote:
Robin, the SA100 spectrum looks very nice, sharp with plenty of spectral features (despite the optical collimation problems). Should 2nd order contamination be a minor problem because of reddened star? The first relatively strong signal is h-beta emission that impacts at about 9600 A. I see several emissions at 7800 and 8500 A (may be there are other emissions I do not see in the background of jpg image).
Thanks Paolo,

Here is the reduced, instrument response corrected version. (Also in fits format for François)
_nova_cep_2013_crop_20130206_937_leadbeater.png
_nova_cep_2013_crop_20130206_937_leadbeater.png (10.07 KiB) Viewed 14740 times
I limited the wavelength range slightly to avoid problems with an overlapping spectrum from another star at the blue end at the red end where the second order might potentially start to become a problem as the flux increases.

For interest, I measured the EW of the H alpha line and compared it with your spectrum from the same night. I got -230 A compared with -205 A for your spectrum. A good agreement I think considering the very large difference in resolution :)

Cheers
Robin

Re: Nova Cep 2013

Posted: Wed Feb 13, 2013 5:14 pm
by Lars Zielke
Hi

I think this is my first post here, although I've been a member for some time.

A spectrum from feb. 10th. reduced, instrument response corrected. To get better a wavelength calibration in the IR domain, I used the OI 7773Å line.

So now I need to identify the other emission lines in the IR domain.
nova-20130210-60s-spec-aras.jpg
nova-20130210-60s-spec-aras.jpg (69.15 KiB) Viewed 14718 times

Re: Nova Cep 2013

Posted: Fri Feb 15, 2013 4:43 pm
by ivan degennaroaquino
Really nice spectra!
The magnitude is raising pretty fast sadly. Greetings to everybody!

Ivan

Re: Nova Cep 2013

Posted: Fri Feb 15, 2013 7:49 pm
by Lars Zielke
Hello

The emission line at around 7122 Å ? Where is that emission coming from?

Cheers
Lars

Re: Nova Cep 2013

Posted: Sat Feb 16, 2013 4:48 am
by Francois Teyssier
Spectre du 14-02
Pas facile, le continuum s'effondre. Seule Ha reste évidente.
Mag 13.3 dans le vert et 11 dans le rouge (raie Ha)

Image

François

Re: Nova Cep 2013

Posted: Sat Feb 16, 2013 9:28 am
by ivan degennaroaquino
At 7135A usually an Argon line [Ar III] is strong in late spectra. It could be, given the fast decline of the nova. Nice result from last spectrum Francois, no more Fe emission.

Re: Nova Cep 2013

Posted: Sat Feb 16, 2013 12:01 pm
by Francois Teyssier
Hello Ivan and Lars,

1. In spectra obtained with Lisa at R=1000, the wave lenght of the unidentified line is 7116 (far from [Ar III] 7135
2. In these *early* spectra, we have not other nebular, forbidden lines

So I doubt that the line could be [Ar III]

In the geat list of line published in Williams 2012, there's no line between HeI 7065 and [Ar III] 7135

Waiting for your comments, Ivan,

Cheers

François

Williams 2012 : http://arxiv.org/ftp/arxiv/papers/1208/1208.0380.pdf





PS : do you envisage to come to OHP spectro party this year?