  Beginning in 1995 June, we have obtained an observation of M87 with the ROSAT
High Resolution Imager (HRI) every 6 months. We present the measurements of
X-ray intensity for the core and knot A through 1998 January. We find
significant changes in both components. For the core, intensities measured in
95 Jun, 96 Dec, and 97 Dec are roughly 30% higher than values obtained at three
intervening times. For knot A, a secular decrease of approximately 15% is
interrupted only by an intensity jump (3 sigma) in 1997 Dec. Because the
background used for subtraction is probably underestimated, we suspect the
actual variation is somewhat greater than these values indicate.
