Affiliation
URSA Astronomical Association, Variable Star Section (Finland) (URSA)
Sat, 03/07/2015 - 08:20
Hello!
I just read an alert notice about symbiotic nova ASAS J174600-2321.3. It seems to be a really interesting object!
I was wandering, what symbiotic novae actually are. I understand novae and symbiotic variables, but what is a symbiotic nova? I read from wikipedia, that symbiotic novae stay in maximum for decade or more! How is that possible? Nova-eruptions shouldn't be that long? What is the mechanism that drives the outbursts in symbiotic novae?
Best regards,
Juha
Finland
Hello,
Symbiotic nova is nova phenomenon which occurs in a symbiotic system (hot compact object often a white dwarf + red giant + nebula created by the strong wind from the red giant, excited by the hard radiation from the WD)
So, this is a thermonuclear runaway which occurs in the accreted envelop at the surface of the WD, but slow, or very slow : AG Peg began its outburts ~ 1850, reached its maximum luminosity in 1871 and slowly decline during more than a century.
PU Vul outburst throw AAVSO observations (note the eclipse)
http://www.astronomie-amateur.fr/ResultatsSpectro/PU_Vul/AAVSO_PU_Vul_Vis.png
List of symbiotic novae :
AG Per, RT Ser, RR Tel, PU Vul
V1016 Cyg, V1329 Cyg, HM Sge
V407 Cygni showed a nova outburst in 2010
See spectroscopic evolution :
http://www.astronomie-amateur.fr/feuilles/Spectroscopie/SyS/V407Cyg.html
A review by Joanna Mikolajewska :
http://arxiv.org/abs/1011.5657
Best regards,
François Teyssier
Thank you very much for your answer, François!
I'm still wondering, what is the mechanism that drives the 'traditional' nova-eruptions and those very slow outbursts in symbiotic novae? Why traditional novae are rapid, explosive events, while symbiotic novae are extremely slow? What is the difference between these two? Is the rate of accretion the determining factor? Is it so, that when the rate of accretion is high, the consequent nova outburst is a rapid, traditional nova? And when the rate of accretion is slower, then the thermonuclear reaction is much slower, as is the case with the symbiotic novae?
Regards,
Juha
Finland