Recently , Weinberg proposed a scenario where Goldstone bosons may be masquerading as fractional cosmic neutrinos .
We calculate the energy loss rates through the emission of these Goldstone bosons in a post-collapse supernova core .
Invoking the well established emissivity bound from the Supernova 1987A observations and simulations , we find that nuclear bremsstrahlung processes can notably impose a bound on the Goldstone boson coupling to the Standard Model Higgs , g , dependent on the mass of the associated radial field , m _ { r } .
For m _ { r } large enough compared with the temperature in the post-collapse supernova core , our bound is |g| \lesssim 0.011 ( m _ { r } / 500 ~ { } { MeV } ) ^ { 2 } , very competitive to that derived from collider experiments .