2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/1315Studies of the lensed quasar ${\rm Q}0957+561 {\rm A,B}$ have shown evidence for microlensing in the brightness history of the quasar images. It had been suggested that a frequency offset between the brightness fluctuations in each of the two images might possibly be caused by gravitational radiation generated by a massive black hole binary at the center of the lensing galaxy. This paper demonstrates that the fluctuations produced by such a source of gravitational waves will be too small to account for the observed frequency offsets.10 pages, 1 fig; submitted to ApJAstrophysicstext