Boson stars (https://en.wikipedia.org/wiki/Exotic_star) are hypothetical, exotic matter, models of stars. They usually rely on exotic particles like axions.
However, Helium-4 is considered to be a boson and Helium-3 a fermion (Why are He-4 nuclei considered bosons, and He-3 nuclei considered fermions?)
So, if by any chance, we found a compact body made only of Helium-4 would it be considered a boson star?
And if it was made entirely out of Helium-3, would it be a fermion star?
There are compact objects made almost entirely of helium, they are called helium white dwarfs. In principle they are the ultimate fate of stars with an initial mass too low to ignite helium in their cores at the end of their main sequence lives $(<0.5 M_\odot )$.
The universe is not yet old enough to have produced helium white dwarfs like this. Instead, these objects are formed in binary systems where there is mass loss and exchange between the components.
These stars are to all intents and purposes like other white dwarfs, supported by electron degeneracy pressure. The helium ions are far too hot to form a condensate and even if, trillions of years into the future, they were able to cool significantly, the stars would just "freeze" into a crystalline form.
At room temperature, He$_4$ is not particularly exotic. Near absolute $0$ it becomes a Bose condensate.
In a star at very high temperatures, it would become a plasma of He$_4$ nuclei and electrons.
