Nuclear Astrophysics

Rare isotope sheds light on how dead stars re-ignite

Rare isotope sheds light on how dead stars re-ignite: Novae are stellar element-making explosions caused when a white dwarf, the carbon-cinder of a once giant star, accretes hydrogen-rich material onto its surface from a companion star. A key to help astrophysicists better understand novae is through determining the rates of reactions that create and destroy the key rare isotopes they're observed to produce, including sodium-22 (22Na). As reported in Physical Review C (2016) scientists used DSL to determine, for the first time using the Doppler-shift attenuation method, the lifetimes of several energetic states magnesium-23 (23Mg) the rare isotope that dominates the destruction of 22Na. The researchers' more precise lifetime measurements of related states help explain the structure and behaviour of these rare isotopes and thus the underlying nuclear physics driving novae.