2024RAA....24j5007H

Nova outbursts are the results of thermonuclear runaways, which occur when sufficient material accretes on the surfaces of white dwarfs (WDs). Using the MESA code, we construct a detailed grid for carbon-oxygen and oxygen-neon-magnesium novae. By employing population synthesis methods, we conduct a statistical analysis of the distribution of novae in the Milky Way. In our models, on average, a typical nova system may undergo about 8000 eruptions and the Galactic nova rate is ∼130 yr^–1. The C, N, and O elements in nova ejecta are strongly affected by the mixing degree between WD core and accreted material. Our results show that the average value of ¹²C/¹³C in nova ejecta is about an order of magnitude lower than that on the surface of a red giant, that for ¹⁶O/¹⁷O is about 5 times lower, and that for ¹⁴N/¹⁵N is about 1.5 times lower. The annual yields of ¹³C , ¹⁵N, and ¹⁷O from nova ejection are larger than those from AGB stars. This indicates that compared to a red giant, nova eruptions are a more important source of the odd-numbered nuclear elements of ¹³C , ¹⁵N, and ¹⁷O in the Galactic interstellar medium.