  Spontaneous wavefunction collapse models, like the Continuous Spontaneous
Localization, are designed to suppress macroscopic superpositions, while
preserving microscopic quantum phenomena. An observable consequence of collapse
models is spontaneous heating of massive objects. Here we calculate the
collapse-induced heating rate of astrophysical objects, and the corresponding
equilibrium temperature. We apply these results to neutron stars, the densest
phase of baryonic matter in the universe. Stronger collapse model parameters
imply greater heating, allowing us to derive competitive bounds on model
parameters using neutron star observational data, and to propose speculative
bounds based on the capabilities of current and future astronomical surveys.
