Transcient ASASSN-cv

[Tim Lester]

Here is my June 23rd spectra of ASASSN-cv that François alerted us to:



Tim

[Francois Teyssier]

Nice !
Clearly a dwarf nova outburst
Strong blue continuum, the classical narrow component of Balmer lines in emission in a broader absorption and CIII/NIII blend 4640 and He II 4686 in emission.
Congratulations (also for Paolo's spectrum)

VSNET observers in photometry found very clear presence of early superhumps
(amplitude 0.07 mag). The period is 0.0591(1) d.
The object is confirmed to be a bright WZ Sge-type
dwarf nova with prominent early superhumps.
The mean magnitude was around 11.2-11.3.
(vsnet-alert 17404)


François

[Paolo Berardi]

Great spectrum Tim!

This is my observation of 22.9 june with Lhires III 150 (R~650)



Electronic finder field:



François, thank you for your valuable spectral analysis and support!

Clear skies!
Paolo

[Francois Teyssier]

Nice spectra !

ATel#6258 http://www.astronomerstelegram.org/?read=6258 relates the observations of Paolo and Tim

Spectra in the Aras Data Base : http://www.astrosurf.com/aras/Aras_Data ... fNovae.htm

All the best,

Francois

[Paolo Berardi]

AAVSO lightcurve of dwarf nova:



"Zoom" on a V mag photometric session shows super-humps (here ~1.4h period, 0.07 mag ampl.), typical feature of WZ Sge (no previous outbursts observed) dwarf nova type.



My last observation of 27.857 june:



It seems to me that both h-alpha emission and h-beta wider absorption are now more pronounced.

Paolo

[Tim Lester]

Here is my spectrum for June 27.094 (I didn't get around to processing it right away) compared to the June 23 data, both calibrated to absolute flux .
Total exposure is over 2 hrs so I am averaging over a full super-hump cycle.



Tim

[Francois Teyssier]

Nice result !
The weakening of the continuum is obvious.
An interesting project is to get an outburst of SS Cyg, day after day. SS Cyg, the brightest symbiotic shows a wide variety of outbursts
Cheers,
Francois