[vsnet-outburst 15473] Re: PNV J19150199+0719471: early superhumps?

[Taichi Kato]

> Low resolution spectra taken by Thibault de France yesterday show  h alpha
> in emission not corresponding to a classical nova.
> http://www.hd182989.info/nova
> Intermediate resolution Echelle spectra  were taken from IAC80 Teide show
> a double peak h alpha emission line with carbon lines in emission.
> http://spektroskopieforum.vdsastro.de/viewtopic.php?p=23389#23389
> It seems not to be classical nova spectra.

   So it is a WZ Sge-type dwarf nova with a moderate inclination
(not so high enough to show large-amplitude early superhumps).
But Halpha is stronger than in WZ Sge!

   Please try one full-orbit spectroscopy (time resolution several
minutes, total duration 2 hours).  You will be able to obtain
a spiral pattern like:

http://adsabs.harvard.edu/abs/2002PASJ...54L...7B

   If you can follow the object on several nights, you will be
able to see how the spiral pattern (the result of the 2:1 resonance)
evolves.  Please try.

   If you are not familiar with the 2:1 resonance, see:

http://adsabs.harvard.edu/abs/2002A%26A...383..574O

   Please include He II 4686.  This line will be a good tracer
for this stage of WZ Sge-type outburst.