Classical Novae Simulations*

Classical novae are key for the understanding of galactic chemical evolution and how elements are created in various stellar environments. A classical nova occurs in a close binary system consisting of a white dwarf star and a companion donor (usually a red giant star). The white dwarf does not have enough mass to explode like a supernova, but in this case, it receives mass from its donor companion, then it can start nuclear burning processes that creates heavier isotopes and ejects newly created elements including radioactive isotopes such as ²²Na. 

 

Computer simulations help us understand the nucleosynthesis happening in these systems. WinNet, a single-zone reaction network, promises similar results to other stellar simulation codes while being less computationally expensive since other codes simulate multiple layers of the nova and the thermodynamic evolution while WinNet only focuses on one and uses a fixed thermodynamic trajectory.

 

Nuclear astrophysicists are looking into an isotope that will give us a better understanding of novae. Sodium 22 is the “star” of this project due to its radioactive nature; it radiates gamma rays after it undergoes beta decay. This is very important for us because it allows telescopes to detect it, therefore we will be able to link the abundance of ²²Na with the detected gamma rays.

 

This project aims to compare variation in ²²Na production due to variations in the ²²Na(p, 𝛾)²³Mg reaction rate from WinNet simulations. After performing a simulation, the production of different isotopes is analyzed to determine the effect of rate variation on the ²²Na production. By building computation tools, we analyze and compare final abundances of isotopes considering different reaction rates.