GMTIFS will contribute to the study of exosolar planets by recording near-infrared spectra of young planets at relatively large radial distances from their host stars. The most encouraging system of this type found to date is HR 8799. Four planets are known around this star at distances ranging from 0.37 to 1.77 arcsec. It is expected that systems with similar angular separations and planet contrast ratios will be found by GPI on the Gemini South telescope and SPHERE on theVLT over the coming decade. The GMTIFS IFS and its occulting disks will be used to obtain JHK spectra of these systems.
Knowledge of the spectral properties of planets allows their atmospheric properties to be characterised and compared with those of field brown dwarfs and Solar planets. GMTIFS IFS observations will provide spectral types, temperatures, surface gravities, and chemical compositions for these planets. With these data, we will be able to define evolutionary sequences for significant samples of young planets for the first time.