Presentation #304.03 in the session Space-based Instruments — iPoster Session.
In the thirteen years since a Space Shuttle Atlantis crew installed the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), the ultraviolet instrument has continually expanded humanity’s understanding of the universe. The COS Team presents highlights and user-relevant status updates from recent instrument calibration. These include an improvement to the flux calibration of the FUV modes. New models for standard white dwarf stars prompted revisions to the fluxes of up to 10% at the shortest wavelengths. To overcome sensitivity losses from gain sag and keep the instrument scientifically productive into the 2030s, COS implemented a system of multiple lifetime positions (LPs). Most G130M modes moved to LP5 with HST Cycle 29 in October 2021. Beginning in Fall 2022, long exposures with G160M will move to LP6. Alongside these major changes, the COS team has continued to improve the instrument’s stability, calibration, and user support. By monitoring dark rates, sensitivities, and hotspots, the COS team better characterized the instrument’s detectors. Updates to the CalCOS pipeline enabled the new SPLIT wavecal mode which is essential to operations at LP6 and beyond. The COS team released an evolving suite of Jupyter Notebooks to aid new and returning COS users with common data analysis tasks. COS continues to provide observers with a sensitive view into the ultraviolet universe.