We present the first astronomical results from a 4K<sup>2</sup> Hybrid Visible Silicon PIN array detector (HyViSI) read out
with the Teledyne Scientific and Imaging SIDECAR ASIC. These results include observations of astronomical
standards and photometric measurements using the 2.1m KPNO telescope. We also report results from a test
program in the Rochester Imaging Detector Laboratory (RIDL), including: read noise, dark current, linearity,
gain, well depth, quantum efficiency, and substrate voltage effects. Lastly, we highlight results from operation of
the detector in window read out mode and discuss its potential role for focusing, image correction, and use as a
telescope guide camera.