[Aavso-photometry] Re: RS Oph

[Richard Huziak]

Gord Sarty (SGE) sent me this - but my spectrometer has a big wall to 
the east that I can't see over, so I will not be able to obtain spectra 
of this event until at least a month from now (thus likely not!)....  HUZ

"RS Oph is in the T CrB class of CVs that consists of a giant M star 
with high mass transfer rates (likely by stellar wind because Roche lobe 
overflow would cause runaway shrinkage of the orbit). The high mass 
transfer is what leads to the frequent novae. Also the white dwarf is 
close to the Chandrasekar mass so RS Oph is likely to become a Type Ia 
supernovae someday (not all accreted matter is blown away in the nova).

The Balmer lines are in emission when RS Oph is in a non-nova state and 
the Balmer line ratios (Balmer decrement) seem to be consistent with 
photoionized-recombination emission from a nebula surrounding RS Oph 
left behind from the frequent nova outbursts. (Regular novae don't 
**seem** to have this feature.)  It would be interesting to see how the 
Balmer lines change throughout the outburst."  (ref Warner's book).

Any spectroscopists out there?  :-)

-- 

* * * * * * * * * * * * *
Richard Huziak
Manufacturing Engineering
SED Systems
Saskatoon, SK, Canada
tel. (306) 933-1676
<huziak at SEDSystems.ca>
* * * * * * * * * * * * *