Gemini e-Newscast #50

by xzhangIn this release:
GeMS Science
Successful DSSI Observing Run
GPI has arrived at Cerro Pachón
Recent Meetings: Operations Working Group and Users’ Committee
Scheduled Telescope Shutdowns North and South
Science Operations Staffing Moves


GeMS Science

The first refereed astronomical paper based on observations with the Gemini Multi-conjugate adaptive optics System (GeMS) is now in press. Tim Davidge (Dominion Astrophysical Observatory, Canada) and colleagues from the GeMS and Gemini South Adaptive Optics Imager teams observed the low-mass star cluster Haffner 16 and used pre-main sequence stars to determine its age. Disintegration of such low-mass clusters may account for the observed field population. The natural seeing conditions at the time of the observations were poor (85 percentile), yet the adaptive optics correction resulted in full width at half maximum better than 0.16 arcseconds in the K band (see image below). A Gemini web feature is posted and a preprint is available.


Successful DSSI Observing Run

The visiting Differential Speckle Survey Instrument (DSSI) completed a successful 8-night run at Gemini North last month. The instrument team obtained data for their own programs and on behalf of astronomers from within the Gemini partnership. The team reports that most of the scheduled programs were completed and that the run was “amazingly productive,” resulting in diffraction-limited images as shown in the figure below.

The first image (greyscale) shows the asteroid Hebe which, according to DSSI team-member Elliott Horch, “...is clearly resolved showing its distinct non-round appearance. The scale of the whole image shown is only about 0.5 x 0.5 arcseconds across!" The Principal Investigator for this work is Bill Merline (Southwest Research Institute).

The second image (inset in the lower right corner) shows the star KOI 2626, a candidate exoplanet host (based on observations with NASA’s Kepler mission). According DSSI team-leader Steve Howell (and PI for this program), ”It shows that the host star actually is not single but has two companions, a slightly brighter one in the lower right and a slightly fainter one in the lower left. The separations from the central star are 0.2 and 0.16 arcseconds respectively. The reason it is a notable result is that the star is pretty faint -- 16th magnitude -- yet, with Gemini, we are still able to resolve these 17th-18th magnitude stars very close to the primary star.”


GPI has arrived at Cerro Pachón

The Gemini Planet Imager (GPI) traveled from the University of California Santa Cruz to Gemini South and is now on the summit of Cerro Pachón. GPI remained in crates during the busy Gemini South maintenance shutdown.

Unpacking just began, and GPI was reassembled in the instrument lab on August 29. If everything checks out successfully, GPI will be mounted on the telescope at the very end of October, with first light on sky sometime during November. Because no on-sky commissioning has been completed yet, the instrument will not be part of the regular 2014A call for proposals. However, we are aiming to conduct some early science observations, selected through an open call to the community, during the semester. More details will be provided as the instrument commissioning proceeds.


Recent Meetings: Operations Working Group and Users’ Committee

The semesterly Operations Working Group meeting, engaging representatives from all National Gemini Offices and observatory staff, took place on August 21 and 22. Conducted remotely, meeting times were spread over two days in order to be reasonable for most participants around the world. The key outcome of the meeting was to set the semester 2014A Call for Proposals, which will be released August 30.

The Users’ Committee for Gemini (UCG) completed their annual meeting in Hilo as well on August 26 and 27. After an evening summit visit on August 25, the meeting commenced with key topics including plans for a user-contributed data reduction forum and new visiting observing modes. Watch for the full report from the meeting to be posted soon on the Gemini website. The UCG aims to represent the broad user experience, so please continue to let them know of your needs at any time. Member names and contact information are posted here.

Scheduled Telescope Shutdowns North and South

The scheduled shutdown at Gemini South is complete, and regular science operations have resumed. In addition to regular work on the Acquisition and Guiding Unit, optical maintenance was done on both GMOS and GCAL, the two major chiller units were relocated and a newer, more efficient model was installed, and work commenced to replace all of the older computer racks. The latter, a huge project, involved the extraction of computers and their installation in a temporary rack before reinstalling them back into the new racks. We expect this work to be completed as planned, shortly after the main engineering shutdown. Gemini North will be closed beginning September 10 for the coating of the primary mirror, which was delayed following water damage to some of the coating equipment in the winter.

Science Operations Staffing Moves

As of July 1, Sandy Leggett is the Head of Science Operations at Gemini North. This change coincides with Inger Jorgensen’s move to become Deputy Associate Director for Operations. Steve Margheim, Associate Scientist at Gemini South, is now Chair of the International Time Allocation Committee, a former role of Sandy’s. Thanks and congratulations to all for taking on these new positions!