  The actinides, such as the uranium (U) element, are typically synthesized
through the rapid neutron-capture process (r-process), which can occur in
core-collapse supernovae or double neutron star mergers. There exist nine
r-process giant stars exhibiting conspicuousUabundances, commonly referred to
as U-rich giants. However, the origins of these U-rich giants remain ambiguous.
We propose an alternative formation scenario for these U-rich giants whereby a
red giant (RG) engulfs an Earth-like planet. To approximate the process of a RG
engulfing an Earth-like planet, we employ an accretion model wherein the RG
assimilates materials from said planet. Our findings demonstrate that this
engulfment event can considerably enhance the presence of heavy elements
originating from Earth-like planets on the surfaces of very metal-poor stars (Z
= 0.00001), while its impact on solar-metallicity stars is comparatively
modest. Importantly, the structural and evolutionary properties of both very
metalpoor and solar-metallicity stars remain largely unaffected. Notably, our
engulfment model effectively accounts for the observed U abundances in known
U-rich giants. Furthermore, the evolutionary trajectories of U abundances on
the surfaces of RGs subsequent to the engulfment of Earth-like planets
encompass all known U-rich giants. Therefore, it is plausible that U-rich
giants are formed when a RG engulfs an Earth-like planet.
