Multi-Mission Collaboration: Update on the EUV Sky

Launched in 1992, NASA's Extreme Ultraviolet Explorer (EUVE) satellite is now conducting its 8th Cycle of Guest Observer pointed observations. During the last three Cycles, the EUVE Project and the independently directed EUVE Science Advisory Board have worked together to implement key projects involving close collaboration with numerous observatories to carry out multi-mission and -wavelength coordinated observations, as well as to conduct large (> 700 ksec) observing programs. Multi-wavelength observations have proved to be an important tool in understanding emission processes in celestial objects from CVs to AGN. Providing a bridge between the X-ray and UV portions of the electromagnetic spectrum, EUVE has played a pivotal role in performing simultaneous observations with both ground- and space-based observatories. In fact, in order to facilitate multi-wavelength coordinated observing campaigns the EUVE Project has provided, with only minimal scientific justification, EUVE observing time to researchers with approved time on the ASCA, RXTE, and Chandra satellites. In addition, EUVE has continued to coordinate observations with numerous other space- and ground-based missions. The Project's streamlined mission operations team has worked hard to support last-minute changes to the short-term observing schedule, which has improved EUVE's flexibility and effectiveness in undertaking coordinated campaigns, and thereby enhanced the overall science return of all participating observatories. Another of EUVE's recent key projects has been the support for large observing programs with long associated exposure times. These programs have involved month-long observations of single targets as well as shorter observations of large groups of similar or neighboring targets. Such large programs, many of which are coordinated with other observatories, have provided researchers with new observing opportunities for performing deep detailed studies of celestial objects in a manner heretofore ruled out under normal observational constraints (e.g., due to limited exposure time). As a result researchers are gaining a much better and more detailed understanding of many celestial and physical phenomena. Multi-wavelength and long program observations make up a large portion of the available EUVE observing time and continue to yield exciting scientific results. This paper will review some of the recent findings, highlight other unique features of the current observing Cycle, unveal plans for a possible EUVE legacy program, and act as an introduction to other papers being presented in this contributed papers session. This work is funded through NASA/UCB Cooperative Agreement NCC5-138.