1 Exosolar Giant Planet Science GSMT vs. JWST Terry Herter February 12, 2004 Based on material from: “Exosolar Planets” by Lunine for GSMT 4/28/03 “Planet Detection, Characterizing Extra-solar Planets” by Najita, Mueller, Mountain & Strom for GSMT 3/17/03 And GSMT-Report and JWST website

2 EGP science What are the origins of the range of orbital distances and eccentricities? –Metallicity contrast between the planet and star will help understand formation mechanism Characterize Exo-solar planets: –Atmospheric structure, chemistry, rotation, weather, etc. (R = 10 & 200) Key Measurements: –Detection and analysis of free floating EGPs R = –Detection and analysis of bound EGPs R = –Measurement of transits High resolution spectroscopy, limited by systematics!

3 It’s a hard problem Star suppressed by nJy Class II EGP: Cool Jupiter-Mass Planet at 1.5 AU Ammonia gaseous; water clouds in troposphere, enhancing NIR reflectivity Planets are faint and near bright objects.

4 Model of young EGP Figure from Lunine: Flux (mJy) at Earth vs. wavelength (microns) for a one Jupiter mass EGP at 10 8 years of age, 10 parsecs distance, isolated. Spectra for R = 1000, 100, and 10 are shown (the latter two displaced for clarity) along with corresponding GSMT sensitivities, displaced in proportion to the corresponding spectra. GSMT sensitivities, courtesy M. Mountain, are for a 104 second exposure, S/N=10, with 4 x 4 pixels across the point source and a GSMT emissivity of 10%.

5 Sensitivity: GSMT vs. JWST GSMT is best for < 3.5  m

6 GSMTJWST  m  5  D (mas) 10pc (AU) 5  D (mas) 10pc (AU) GSMT wins big, but JWST has stability. Spatial Resolution

7 Complementarity GSMT – –Best in near-IR from both sensitivity and spatial resolution considerations –Look for EGPs closest to stars JWST – –Best in thermal IR –Look for cooler, more distant EGPs –Look for “free floaters” –Highly stable PSF?