GeminiFocus December 2012 | Page 30

Figure 2. GPI with the UCLA Integral Field Spectrograph installed. Good progress has been made on these fronts, even though the NGSWFS is still lacking more optimizations to improve the current limiting magnitude. We are now considering an alternative design using a low-noise detector that would improve both performance and efficiency on-sky. The winter shutdown has also allowed us to advertise the first GeMS results. In particular, our team has presented as many as five talks on GeMS at the 2012 SPIE (the international society for optics and photonics) conference in Amsterdam. The first on-sky GeMS results were definitely one of the main highlights of the meeting. At the end of August 2012, we made a call for System Verification (SV), offering around 60 hours of GeMS + GSAOI (the Gemini South Adaptive Optics Imager, a NearInfrared camera working with GeMS) to our users. We received about three times as many proposals as we required; the final selection can be seen at: http://www. gemini.edu/sciops/instruments/gsaoi/systemverification?q=node/11895. We also offered GeMS/GSAOI for 2013A in a shared-risk mode for a total of around 100 hours. We received a very good response from the community to that as well, with, once again, an over-subscription ratio of three. 30 GeminiFocus By October 19th, GeMS went back on-sky with a three-night run to work out all the Laser and Laser Guide Star Facility systems. A second commissioning run took place at the beginning of November, aiming at optimizing and stabilizing performance, as well as smoothing operations. Unfortunately, a combination of low laser power, low sodium content, and bad weather/ seeing prevented us from accomplishing all the tasks planned. Low sodium return is currently one of the main performance limitations of GeMS. However, with a little more work, we should improve the laser’s power and performance in the current and upcoming semesters. To illustrate how GeMS performed in the November run, the image in Figure 1 shows a portion of the star cluster NGC 1851 acquired in H-band. The full-width at half-maximum of the stars are around 120 milliarcseconds and uniform across the 85 x 85 arcsecond field-of-view of GSAOI. Although not at the level of the diffraction limit, the image still offers a significant improvement compared to uncorrected images. A third commissioning was run in December, and SV will start in January. This New Year’s Eve will be a laser night, wishing the best for GeMS in 2013. Gemini Planet Imager Nears Acceptance Testing The Gemini Planet Imager (GPI) continues its march toward becoming the nextgeneration extrasolar planet imager and spectrograph at the Gemini Observatory (Figure 2). The GPI team is now preparing for the instrument’s Acceptance Test Stage (planned in the first quarter of 2013), where the completed instrument will be subjected to several tests to verify its performance and usability. If all goes well, acceptance testing December2012