Argus, CTIO's venerable fiber-fed, multi-object spectrograph, which has been in service for nine years, will soon be replaced with an improved version of the WIYN Hydra. With six times as many fibers, better positioning accuracy and superior performance in the UV, CTIO's "Hydra II" will have significantly higher performance than Argus and is scheduled to go into full service during 1999. Proposals for shared risk observing during the first semester of 1999 will be accepted next year. Hydra II is expected to become fully operational for routine observing during the second semester of 1999.
Hydra will be installed during the second semester 1998, which necessitates the removal of Argus towards the end of the first semester. This will allow new fibers and a new R/C ADC corrector to be installed and the spectrograph modified. Argus decommissioning has been tentatively scheduled for May 1998, the exact date depending on demand for final use of the instrument. Once Argus has been decommissioned, there will be no multi-object spectrograph available at CTIO until Hydra II is functional. This will be roughly the period May 1998-January 1999.
T. Ingerson, R. Schommer