SIMBAD references

Variability of southern extragalactic radio sources on time scales of 1-10 days has been studied at 1.42GHz using a 30-m telescope with a declination range from -9deg to -90deg. Measurements of 18 sources were made in 11 successive nights in each of two observing sessions. Most of the flat-spectrum sources vary a few percent on time scales mainly in the range 2-4 days, a behaviour that could be originated, or at least strongly influenced, by refractive processes in the interstellar medium. A few sources displayed a higher level of activity with rms fluctuations of ∼6%. This latter variability could be partially intrinsic to the sources.