First astronomical application of a cryogenic transition edge sensor spectrophotometer

We report on the first astronomical observations with a photon-counting pix el detector that provides arrival time (delta t = 100 ns) and energy (delta E-gamma less than or equal to 0.15 eV) resolved measurements from the near -IR through the near UV. Our test observations were performed by coupling t his transition edge sensor device to a 0.6 m telescope; we have obtained th e first simultaneous optical near-IR phase-resolved spectra of the Crab pul sar. A varying infrared turnover gives evidence of self-absorption in the p ulsar plasma. The potential of such detectors in imaging arrays from a spac e platform is briefly described.