Absolute Measurements of the Flux of Cassiopeia a and Taurus a at 1.87 Centimeters

Using the 20-foot horn-reflector antenna at Crawford Hill, we have made absolute flux measurements of Cas A and Tau A during April, May, and August 1970. Our result for Cas A is 350 X 10-26 W Hx-' with a 99 percent confidence absolute error of 5.2 percent, in good agreement with published values. Our Tau A data, however, show a temporal decline of 20 percent during the period of observation a change considerably greater than the sum of the known components of experimental error. Published values for the flux of Tau A near this wavelength lie between our maximum and minimum values.