Cosmic Origins Spectrograph: On-Orbit Structural and Thermal Stability.
Abstract
After installation of the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, two of the experiments characterizing the on-orbit performance of COS were the COS/NUV and the COS/FUV Structural and Thermal Stability programs (IDs 11480,11493).
In each of three observations, the COS shutter was held open for approximately 8 hours of nearly continuous time-tag readouts. 23000s of FUV spectra were obtained of the SMC symbiotic star, Lindsay 358. 23500s of NUV spectra were obtained of the galactic symbiotic star, AG Draconis. The solar analog and HST standard star, P177D, was observed for 18000s in NUV image mode. We report our measurements of the time variation in along-dispersion and cross-dispersion positions and of the FWHM of the spectra and images on the detectors. We report long-term multi-orbit shifts and periodic variations on orbital as well as shorter time-scales. We relate these variations to variations in thermal conditions of the spacecraft and the COS instrument.- Publication:
-
American Astronomical Society Meeting Abstracts #215
- Pub Date:
- January 2010
- Bibcode:
- 2010AAS...21546405S