BIGCAT is the new GPU-based correlator for ATCA. After installation and engineering commissioning finished, science commissioning began in August, with a team of astronomers putting the telescope through its paces. As expected, this revealed a number of bugs and issues which the BIGCAT team were quick to fix. The image above, from a BIGCAT Update given at September’s ATUC meeting, show a selection of images from the science commissioning observations. Clockwise from top: the giant elliptical radio galaxy IC 4296 (PKS 1333-33), the Galactic X-ray binary Circinus X-1, the Galactic star-forming region G333.6-0.2, and the field surrounding the ATCA’s primary flux density calibration, PKS 1934-638 (compared to an image from the Rapid ASKAP Continuum Survey). The ATCA has been offline from Sep 1 for work on antennas as part of the ATCA infrastructure upgrade. Scheduled observing in the BIGCAT era will start on Oct 20th.