  The Standard Model of particle physics is a $SU(3)_c\times SU(2)_L\times
U(1)_Y$ gauge theory that can explain the strong, weak, and electromagnetic
interactions between the particles. The gravitational interaction is described
by Einstein's General Relativity theory which is a classical theory of gravity.
These theories can explain all the four fundamental forces of nature with great
level of accuracy. However, there are several theoretical and experimental
motivations of studying physics beyond the Standard Model of particle physics
and Einstein's General Relativity theory. Probing these new physics scenarios
with ultralight particles has its own importance as they can be a promising
candidates for dark matter that can evade the constraints from dark matter
direct detection experiments and solve the small scale structure problems of
the universe. In this paper, we have considered axions and gauge bosons as
light particles and their possible searches through astrophysical observations.
In particular, we obtain constraints on ultralight axions from orbital period
loss of compact binary systems, gravitational light bending, and Shapiro time
delay. We also derive constraints on ultralight gauge bosons from indirect
evidence of gravitational waves, and perihelion precession of planets. Such
type of observations can also constrain several particle physics models and are
discussed.
