The equation of a circle is \( \operatorname{Re}(z^{2}) + 2\,\operatorname({Im}(z))^{2} + 2\,\operatorname{Re}(z) = 0 \), where \( z = x + iy \). A line which passes through the centre of the given circle and the vertex of the parabola, \( x^{2} - 6x - y + 13 = 0 \), has \( y \) intercept equal to _______.
