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SS Aurigae in outburst

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SXN
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SS Aurigae in outburst

After entering into an anomalously bright minimum in December 2014, SS Aur has just gone into outburst.

lmk
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A Z?

Hmmm, Maybe it looks like its becoming a ZCam :)

 

wkl
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Hi Mike,   last night

Hi Mike,

 

last night - 20150205 18:40UT -  12m,0

Klaus

 

BRJ
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Pseudo standstils of SS Aur

Pseudo standstils of SS Aur are certainly nothing new as I pointed out in another recent thread. In fact reports of occasional examples of them go back at least 40 years according to the original AAVSO Circular. They could very well go back much further in time, but back before the mid 1960's and prior to the era of "Inner Sanctum" observations relative few AAVSO observers were equipped to regularly record stars in the mid to deep 14's.

Certainly, SS Aur is an oddball among the UGSS type dwarf novae, but it is certainly not totally alone in this subgrouping that experiences something akin to Z Cam-like standstills.

J.Bortle   (BRJ)

 

FMT
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ARAS Spectrum

 

A (nice) spectrum obtained by Peter Somogyi (Alpy 600) is post on ARAS Forum

http://www.spectro-aras.com/forum/viewtopic.php?f=5&t=1069

François Teyssier

 

 

WGR
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Spectra of SS Aur

Hello Francois

Thanks for posting this spectra.  Its really nice.  Perhaps this should morph over to the Spectroscopy Forum, but I did not for now.  I was interested in those with experience with spectra and this type of object, to say a few words about what this tells them.

I see the Halpha line in emission.  I also see Hbeta, Hgamma, Hdelta, Hepsilon, Hzeta, and Heta all with either absorption or combination of emission and absorption. 

Does this mean there is a dense thick cold cloud that absorbs lots of blue light--almost seems like the bluer the emission, the larger the absorption.  The Ha is almost not affected.  Does this mean that the Ha emission occurs first and is located outside the absorption cloud? 

What's going on here?

 

WGR

Gary

FMT
FMT's picture
    Hello Gary At quiescence

 

 

Hello Gary

At quiescence the spectrum shows emission lines. During the ouburst, the emission lines are gradually overwhelmed by the increasing continuum and the development of broad absorptions.
At maximum light, in most CV, the typical feature is a broad absorption and a narrower emission. As the Blamer decrement is much steeper in the emission than in the absorption lines, H alpha is often in pure emission while other lines are in emission.
The inner accretion disk, optically thick (and complete hydrogen ionization) produces the broad  absorptions, while the emissions are produced in the outer region of the disk.
The shape can vary from one CV to another ; the evolution can also vary from one outburst to another. For example, in-out and out-in outburts produce different evolution in the spectrum of SS Cygni.
You can find the evolution of the spectrum of SS Cygni during an outburst (2010, September)
http://www.astronomie-amateur.fr/feuilles/CV/SS%20Cyg.html
Note that in Peter's specrum, you have also He II 4686.

 

Regards,

 

François

 

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