VLBI Monitoring of the bright gamma-ray blazar PKS 0537-441

One of the defining characteristics of BL Lacertae objects is their strong variability across the electromagnetic spectrum. PKS 0537−441 is one such object and is one of the most luminous blazars from radio to -ray wavelengths. It was detected as a strong and highly variable source by EGRET and has been reported several times to be in an active state by Fermi. It is one of the brightest -ray blazars detected in the southern sky so far. The TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry) program is monitoring PKS 0537−441 at VLBI resolutions. We present 8.4GHz and 22GHz images of the milliarcsecond scale structure. We also present our ongoing analysis of the spectral and temporal changes in this object.