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N OPH 12 (PNV J17260708-2551454) misclassified?

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lmk
lmk's picture
N OPH 12 (PNV J17260708-2551454) misclassified?

One thing to get used to with the new forums, now one has to figure out the right category for the subject...haha. Hope this is the place for this.

Question: Since this "nova" was discovered about 2 months ago, hasn't it exhibited highly uncharacteristic behavior for a nova? Rather than peak and decline, or rebrighten once or twice, it has hung around near its max, oscillating sort of randomly by 2 magnitudes.  Any ideas about this? The weirdest nova I've ever seen LOL!

Mike LMK

FMT
FMT's picture
N Oph 2012 spectra

Several spectra by Christian Buil :

http://www.astrosurf.com/buil/nova_oph2012/obs.htm

show the typical features of a Fe Nova near maximum light (narrow lines, P Cygni profiles, many Fe II lines.

 

Best regards

François Teyssier

 

 

lmk
lmk's picture
But isn't the light curve

But isn't the light curve atypical for an Fe Nova? Essentially constant after outburst? Maybe showing decreasing oscillations, but no real sign of a decline? Could these same spectral features be found in other types of systems?

Mike LMK

FMT
FMT's picture
Hi Mike, During transition

Hi Mike,

During transition phase, the light curves may show a wide variety of appearance :

http://arxiv.org/pdf/1004.3698v1.pdf

Obviously, as you note, N OPH 12 doesn't show a stereotypical lightcurve.

See noticely Fig.

 

Best regards

 

François Teyssier

 

 

lmk
lmk's picture
F-Type?

Thank you for the good article Francois! Well, based on the classification system therein, I would say this nova appears to be the "flat-top" F-type, maybe with some jitters or oscillations, even though those sem to be dampening out now. Looks like its most closely related to V849 Oph of those 4 such known ones, which seemed to display declining oscillations at the beginning too. Unless there's something about its spectrum that doesnt fit the F-type?

Anyway, it could be due to begin the rapid decline phase.

A most interesting type, as the article says there is no known physical explanation for the behavior! Any hypothesis out there?

Mike LMK

lmk
lmk's picture
Decline

Based on several recent observations, it appears to be starting a more rapid decline. This is looking more like a nova now. Still its behavior since outburst is pretty unique, sort of "Flat-top" but with large oscillations which damp out somewhat. Maybe this could be a new "FO" classification?

Mike LMK

FMT
FMT's picture
Hi Mike, I think you'll

Hi Mike,

I think you'll find somme answers in this publication :

http://arxiv.org/abs/1010.5611v1

On the rebrightnings of classical novae during the early phase, Tanaka & al., 2010

Some examples of novae with similar light curves.

See also spectra of Nova Sco 2012

by Terry Bolsen, Bernard Heatcote (Australia) and Christian Buil (France) :

http://users.northnet.com.au/~bohlsen/Nova/nova_scorpii_2012.htm

with a very nice animation

and :

http://www.spectro-aras.com/forum/viewtopic.php?f=6&t=336

Best regards

François Teyssier

 

 

chergen
chergen's picture
Nova Oph 2012 Continues to Surprise

Over the past few days this nova has experienced a dramatic drop in brightness. After spending the past 3 months since discovery bouncing between V ~ 10.5 and 12.5, the nova was observed last night (Jun 29.289) at V = 15.95 +/- 0.07. It was V = 13.64 a night earlier (Jun 28.291) and V = 12.73 the night before that (Jun 27.297).

Not only did this nova have a long plateau near maximum but it now seems to be experiencing a dust dip.

A very interesting object and one that I'm having fun following.

- Carl Hergenrother (HCW)

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