CNO Abundances and Hydrodynamic Models of the Nova Outburst

Abstract

The accretion of hydrogen onto a white dwarf star ignites a thermonuclear runaway in the accumulated envelope, leading to luminosities up to 1 million times that of the Sun and a high velocity mass ejection that produces a remnant shella classical nova eruption 1,2 . Close to the upper mass limit of a white dwarf 3 (1.4 Msun), rapid accretion of hydrogen (~10 -7 Msun/yr) from a binary star companion leads to frequent eruptions on timescales of years 4,5 to decades 6 . Such systems are known as recurrent novae. The ejecta of recurrent novae, initially moving at up to 10,000 km/s (7) , must sweep-up the surrounding interstellar medium and evacuate cavities around the nova binary. No remnant larger than one parsec from any single classical or recurrent nova eruption is known 8,9,10 , but thousands of successive recurrent nova eruptions should be capable of generating shells ~100-1,000 times this size.Here we report that the most rapidly recurring nova, M31N 2008-12a, which erupts annually 11 , is surrounded by such a nova super-remnant with a projected size of at least 134

Theoretically Inferred Masses of the White Dwarf Components of Common Nova Systems

“…The arguments presented in this paper arise within the framework of the thermonuclear runaway model, the basic validity of which has been confirmed by numerical hydrodynamic studies (Starrfield et al, 1972Sparks et al,1978;Prialnik et al, 1978Prialnik et al, , 1979. A survey of those features of the model relevant to our present discussion is presented in the following section.…”

Soft X-Ray Emission from Classical Novae in Outburst

“…Once the outer layers begin to expand, the effective temperature declines steadily until the expanding envelope reaches temperatures of ~ 10 4 K. At this time the outer layers of the expanding envelope become optically thin and the pseudo-photosphere moves inward in mass to deeper and hotter layers.. In addition, observations show and theory predicts that the shell source continues to produce energy at very high rates keeping the evolving nova radiating at near Lsdd-This constant luminosity phase was one of the first predictions of the thermonuclear runaway theory to be confirmed by observations (Starrfield et al 1972;Gallagher and Code 1974). The simulations show that it will last until almost the entire accreted envelope has been ejected or burned.…”

Observational signatures of SNIa progenitors, as predicted by models

“…They are powered by thermonuclear runaways (TNR) in their WD's hydrogen-rich envelopes (Starrfield et al, 1972). After ejecting their erupting envelopes, novae self-extinguish (Prialnik et al, 1978).…”