β decay of the [Formula Presented] nuclide [Formula Presented] has been studied at the ISOLDE PSB Facility at CERN. [Formula Presented] ions were produced in spallation reactions in a Nb foil using the 1 GeV proton beam and studied by means of β-delayed proton, β- and γ-ray spectroscopy. The half-life and the β-decay energy of [Formula Presented] were determined using the decay of protons and positrons. These results: [Formula Presented] and [Formula Presented] and the first observation of the β branch to the 207 keV level in [Formula Presented] makes the extension of the systematics of Gamow-Teller matrix elements of mirror nuclei up to [Formula Presented] possible. The Gamow-Teller strength of the same magnitude as that of the [Formula Presented]-shell mirror nuclei is observed for the ground-state transition.