  A sub-fraction of dark matter or new particles trapped inside celestial
objects can significantly alter their macroscopic properties. We investigate
the new physics imprint on celestial objects by using a generic framework to
solve the Tolman-Oppenheimer-Volkoff (TOV) equations for up to two fluids. We
test the impact of populations of new particles on celestial objects, including
the sensitivity to self-interaction sizes, new particle mass, and net
population mass. Applying our setup to neutron stars and boson stars, we find
rich phenomenology for a range of these parameters, including the creation of
extended atmospheres. These atmospheres are detectable by their impact on the
tidal love number, which can be measured at upcoming gravitational wave
experiments such as Advanced LIGO, the Einstein Telescope, and LISA. We release
our calculation framework as a publicly available code, allowing the TOV
equations to be generically solved for arbitrary new physics models in novel
and admixed celestial objects.
