  We present a determination of the cosmic microwave background dipole
amplitude and direction from the COBE Differential Microwave Radiometers (DMR)
first year of data. Data from the six DMR channels are consistent with a
Doppler-shifted Planck function of dipole amplitude Delta T = 3.365 +/-0.027 mK
toward direction (l,b) = (264.4 +/- 0.3 deg, 48.4 +/- 0.5 deg). The implied
velocity of the Local Group with respect to the CMB rest frame is 627 +/- 22
km/s toward (l,b) = (276 +/- 3 deg, 30 +/- 3 deg). DMR has also mapped the
dipole anisotropy resulting from the Earth's orbital motion about the Solar
system barycenter, yielding a measurement of the monopole CMB temperature at
31.5, 53, and 90 GHz, to be 2.75 +/- 0.05 K.
