Light weakly interacting particles could be copiously
produced in the Sun which, as a well-understood star, could provide
severe constraints on such new physics. In this work, we calculate
the solar production rates of light gauge bosons (e.g. dark photon)
arising from various U(1) extensions of the standard model. It
is known that the dark photon production rate is suppressed by the
dark photon mass if it is well below the plasmon mass of the medium.
We show that for more general U(1) gauge bosons, this suppression
is absent if the couplings are not in alignment with those of the
photon. We investigate a few frequently discussed U(1) models including
B - L, Lμ - Lτ
, and Le - Lμ(τ)
, and derive
the stellar cooling bounds for these models.