We present a composite light-curve model of the symbiotic nova PU Vul ( Nova Vulpeculae 1979 ) that shows a long-lasted flat optical peak followed by a slow decline .
Our model light-curve consists of three components of emission , i.e. , an outbursting white dwarf ( WD ) , its M-giant companion , and nebulae .
The WD component dominates in the flat peak while the nebulae dominate after the photospheric temperature of the WD rises to \log T ( K ) \gtrsim 4.5 , suggesting its WD origin .
We analyze the 1980 and 1994 eclipses to be total eclipses of the WD occulted by the pulsating M-giant companion with two sources of the nebular emission ; one is an unocculted nebula of the M-giant ’ s cool-wind origin and the other is a partially occulted nebula associated to the WD .
We confirmed our theoretical outburst model of PU Vul by new observational estimates , that spanned 32 yr , of the temperature and radius .
Also our eclipse analysis confirmed that the WD photosphere decreased by two orders of magnitude between the 1980 and 1994 eclipses .
We obtain the reddening E ( B - V ) \sim 0.3 and distance to PU Vul d \sim 4.7 kpc .
We interpret the recent recovery of brightness in terms of eclipse of the hot nebula surrounding the WD , suggesting that hydrogen burning is still going on .
To detect supersoft X-rays , we recommend X-ray observations around June 2014 when absorption by neutral hydrogen is minimum .