GeminiFocus 2013 Year in Review | Page 51

After finishing optical rework in April 2013 (Figure 2), F2 stepped closer to its final round of commissioning observations when it was moved from the Gemini South summit instrument lab onto port 5 of the Instrument Support Structure on June 11, 2013. The first preliminary science queue data were obtained July 19th, and regular queue observations began in late September. F2 began obtaining data in “shared-risk” mode in August 2013 and between then and mid-December has executed 15 queue programs. Despite this exciting milestone, challenges remained. One problem involved the instrument’s On-Instrument Wavefront Sensor (OIWFS) used to optimize the delivered image quality to the camera. During on-sky checks on the night of August 24th, an alignment problem with the OIWFS became apparent. An inspection quickly followed, and the mechanism was realigned as precisely as possible with minimum intrusion (i.e., without moving other optical components). PIs with programs in the 2013B queue were informed of the possibility of reverting to the use of PWFS2, and observations were prepared for either option, allowing queue observations to continue. An additional problem was discovered with repeatability of the Lyot wheel mechanism, but a solution was identified and the problem resolved in December. However, delivered image quality is a significant remaining issue, and is still under active investig