GeminiFocus October 2018 | Page 20

Figure 3 .
Gemini day crew members Clayton Ah Hee ( left ) and Rody Kawaihae
( right , kneeling ) assist Sloane Wiktorowicz ( center ) in installing
Credit : Alison Peck
In early August , we hosted a science visit by Principal Investigator Sloane Wiktorowicz ( The Aerospace Corporation , El Segundo , California ) with his instrument POLISH-2 ( Figure 3 ). Aimed at exoplanet reflection polarimetry , POLISH-2 is available to the community , and we encourage everyone to have a look at the Call for Proposals and contact Sloane ( using the details provided there ) if they wish to take advantage of this cutting-edge polarimeter on Gemini North . The amount of time our visiting instruments are available on the telescope is driven by the number of successful proposals , so we encourage everyone to go for it ! The exciting results of this recent observing run are being prepared for publication now .
MAROON-X : Coming Soon !
MAROON-X is the hotly anticipated new spectrograph in construction at the University of Chicago that will be coming to Gemini North as a visiting instrument next year ( Figures 4 and 5 ). MAROON-X is expected to have the capability to detect Earth-size planets in the habitable zones of mid- to late-M dwarfs using the radial velocity method . The instrument will be a high-resolution , benchmounted spectrograph designed to deliver 1 meter per second radial velocity precision for M dwarfs down to and beyond V = 16 . More information about MAROON-X can be found in the January 2018 issue of GeminiFocus .
As this instrument will be located in the pier lab , under the telescope , in its own thermally controlled enclosure , Gemini has commissioned a Front End to interface to the Instrument Support Structure . This unit will hold the optical fiber that runs to the instrument and will also include some optics and electronics , as shown in Figure 4 . The Front End
Figure 4 ( above left ). The MAROON-X Front End nearing completion at the lab in Chicago .
Credit : Andreas Seifahrt
Figure 5 ( above right ). MAROON-X guide camera diagram showing the object fiber in the center ( backilluminated ), surrounded by three single-mode fibers . These three fibers allow us to triangulate the position of the object fiber in real time during the observations . A tip-tilt mirror is used to center the stellar image on the object fiber . For lab testing , an “ artificial star ” was created by placing a pinhole at the nominal telescope focus and illuminating it with an f / 16 beam . Two sky fibers , placed 20 ” from the object fiber in opposite positions , are used to capture the sky background for a high-dispersion spectrum in MAROON-X and for a time-resolved , low-dispersion spectrum with an external spectrograph . A calibration fiber transports light from the spectrograph room to the telescope ’ s front end and is used to illuminate the object and one of the sky fibers for flatfield and wavelength calibration frames . Credit : Andreas Seifahrt
18 GeminiFocus October 2018