Effect of double stars on the guiding system of the Hubble space telescope

摘要

The interferometric system used for the guidance of HST is sensitive to close binaries, and before the launch of HST it was believed that up to 25% of all guide stars pairs would lead to guidance failure due to duplicity. After nearly 3 years of operation the actual failure rate is below 1%. We have developed a computer simulator to understand the causes of the discrepancy. Our simulation results indicate a failure rate under 2% per guide-star pair in much closer agreement with the observed performance of the guiding system. We show that the failure criterion originally used was much too severe and that the proportion of guide stars in the critical separation range had also been overestimated.