Yuri Cavecchi has done more than anyone IMO to understand the broad properties of thermonuclear bursts. In his latest paper (arXiv:2506.11966) he describes further refinement of his phenomenological model that explains the relative inefficiency of unstable thermonuclear burning at high accretion rates.

The model has several requirements, including a varying distribution of accretion over the neutron star; stable burning (at the equator) coexisting with unstable (at higher latitudes); and significant "pollution" of the burst fuel by ashes dredged up into the fuel layer, possibly by convection. This pollution contribution is now on a firmer basis with support from MESA simulations, and as a whole the model matches the burst observations and potentially allows us to deduce changes in the accretion disk geometry close to the star. The paper is under review by ApJL.

Labels: 2025, papers