Nova Ophiuchi 2015

[Tim Lester]

Spectrum of Nova Oph for 2015-04-16 at R=1980.
According to the AAVSO light curve it is in decline with a Vmag of 11.
I am intrigued by the split lines in particular the two HeI lines at 6678 and 7065. Does this mean that the gases are expanding in two jets towards and away from us?
I would have thought that a symmetrical expansion would produce flat toped broad lines.

_novaoph2015_20150416_311_tlester.png (9.33 KiB) Viewed 8086 times

Tim

[umberto sollecchia]

Bonjour à tous.
Dans mes trois observations, l'étoile de référence ne était pas exactement la hauteur de la nova.
Pour le dernière osservaziomne du 13-04-2015, je ai corrigé pour les différents atomsferica de transmission avec la fonction appropriée du programme ISIS.
Donc, je pense que le continuum est plus correct dans le dernier profil que je ai posté.
Sincèrement Umberto

[Francois Teyssier]

Looks to be very special, Tim

NovaOph2015_20150416_HeI.PNG (29.56 KiB) Viewed 8062 times

Steve will comment during the night

François

[Olivier GARDE]

Evolution of the nova since 72H is very fast.
Here's a graph with spectrum taken the 15th and the last taken this morning.

[Tim Lester]

Nova Oph 2015 for the 18th compared to my last spectrum on the 16th.
I have converted both to flux using AAVSO data (had to extrapolate a bit for the 18th).
I find it very interesting that H beta and the HeI lines have retained their peak intensities
while Ha the continuum and all other lines have decreased.

_novaoph2015.png (12.04 KiB) Viewed 8031 times

Tim

[Christian Buil]

Olivier, I confirm the very large change in the spectral profil (see also Tim's spectrum) on eShel spectrum (R=11000). The double peak structure on HeI 6678 A and 7065 A is also well visible (the flux on the continuum also change - global magnitude of the object). The comparison of 14 and 18 april observation:



(the continuum is normalized to unity in the spectral range 6720-6800 A)

The very intense [OI] line at 5577 A (a quasi monochromatic shape) seem probable the 18.1 April, but the continuum is uncertain:



The line at 5461 A is from the urban sky pollution (Hg line)

... the problem is the very bad observation condition the 18 April in Toulouse (bright sky (haze) and absorption)... the sky image 30 minutes after nova observation (!):



Christian

[Jacques Montier]

Hello,

Nova Ophiuci spectrum on 2015/04/20 with Alpy600.
The target was rather low at 3hUT : 19° in Brittany (France)

20150420_novaoph.png (48.94 KiB) Viewed 7908 times

Regards,

[umberto sollecchia]

Bonsoir à tous, je apporte un nouveau profil de la nouvelle. L'observation a été effectuée dans la nuit du 21/04/2015.

Profilo nova 2015 U Sollecchia.png (10.47 KiB) Viewed 7985 times

Cordialement Umberto

[Francois Teyssier]

Impressive result at mag 11.5, Christian.
Steve is very interested by the spectroscopic evolution, especially the profile of He I lines.
The ejecta is exceptionnally collimated.
New spectra are required for the next week ; medium and high resolution if possible.
An Atel is considered for next week.

The light curve is not typical, with a slow rise. Looks like the nova begins oscillations three mag under the maximum.

NovaOph2015.PNG (14.86 KiB) Viewed 7963 times

All the best,

François

[Joan Guarro Flo]

Hi all:

Nova Oph 2015, in the last night.

Regards, J.Guarro