http://www.rssboard.org/rss-specification 720 XTF Search Results (expand=subject;f1-spectral-Type=X-ray;f2-subject=HEAO-1 All-Sky X-ray Catalog) http://ecuip-xtf.lib.uchicago.edu/xtf/search?expand%3Dsubject;f1-spectral-Type%3DX-ray;f2-subject%3DHEAO-1%20All-Sky%20X-ray%20Catalog Results for your query: expand=subject;f1-spectral-Type=X-ray;f2-subject=HEAO-1 All-Sky X-ray Catalog Thu, 01 Jan 1970 12:00:00 GMT HEAO-1 All-Sky X-ray Catalog. http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/heao1-sky-map/heao1-sky-map.dc.xml Beginning in 1977, NASA launched a series of very large scientific payloads called High Energy Astronomy Observatories (HEAO). The first of these missions, HEAO-1, carried NRL’s Large Area Sky Survey Experiment (LASS), consisting of 7 detectors. It surveyed the X-ray sky almost three times over the 0.2 keV - 10 MeV energy band and provided nearly constant monitoring of X-ray sources near the ecliptic poles. http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/heao1-sky-map/heao1-sky-map.dc.xml Thu, 01 Jan 1970 12:00:00 GMT