A metre-wave outburst from the QSO 1055+018

Observations of the QSO 1055 + 018 with the Culgoora circular array show that the source flux density doubled at 160 MHz and tripled at 80 MHz during the first seven months of 1983, while complementary observations between 0.843 and 15 GHz revealed no significant changes. Since the 80-MHz quiescent brightness temperature probably exceeds the inverse Compton limit of equivalent to 1012K for incoherent synchrotron emission, the extreme-brightness temperatures deduced from the time variability at metre wavelengths may naturally be explained by the brightening of a coherent source. Slow interstellar scintillations provide another possible explanation. (author)