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N OPH 12 (PNV J17260708-2551454) misclassified?

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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

N Oph 2012 spectra
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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

 

 

But isn't the light curve
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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

Hi Mike, During transition
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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

 

 

F-Type?
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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

Decline
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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

Hi Mike, I think you'll
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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

 

 

Nova Oph 2012 Continues to Surprise
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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)

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484