The 2000 outburst of V445 Puppis shows unique properties, such as the absence of hydrogen, the enrichment of helium and carbon, and the slow development of the light curve with a small amplitude that does not resemble any classical novae. This object has been suggested to be the first example of a helium nova. We calculate theoretical light curves of helium novae and reproduce the observational light curve of V445 Pup. Modeling indicates a very massive white dwarf (WD), more massive than 1.3 M⊙. The companion star is possibly either a helium star or a helium-rich main-sequence star. We estimate the ignition mass as several times 10-5 M ⊙, the corresponding helium accretion rate as several times 10-7 M⊙ yr-1, and the recurrence period as several tens of years. These values suggest that the WD is growing in mass and ends up either a Type la supernova or an accretion-induced collapse to a neutron star.
ASJC Scopus subject areas