Oh, come on! Does anyone proofread these articles to do a sanity check? To call that exomoon small at 0.4 the mass of Jupiter is insane. It is massive and the only reason we know it is there. It is likely bigger than any planet in our Solar system except the Jupiter itself.
Located 133 light-years from Earth, an exoplanet may have an exomoon, which would be a world first. However, further studies must be conducted by scientists and astronomers to validate this discovery.