Response to Comment on "A noninteracting low-mass black hole-giant star binary system"

Van den Heuvel and Tauris argue that if the red giant star in the system 2MASS J05215658+4359220 has a mass of 1 solar mass (M-circle dot), then its unseen companion could be a binary composed of two 0.9 M. stars, making a triple system. We contend that the existing data are most consistent with a giant of mass 3.2(-1.0)(+1.0) M-circle dot, implying a black hole companion of 3.3(-0.7)(+2.8) M-circle dot