Recent JWST Science Highlights - Exoplanets

An Image-Plane Algorithm for JWST's Non-Redundant Aperture Mask Data

Why JWST is important:Non-redundant masking on JWST will complement high contrast coronagraphy for exoplanet characterization, as its small inner working angle extends the direct imaging search space much closer to the host star. This study develops an analytic approach to measuring interferometric fringes directly in the image. The image plane approach sidesteps Fourier transform artifacts from small fields of view and bad pixels. We simulate point-source data to estimate contrast, and study anticipated systematic errors on JWST-NIRISS. JWST will provide unprecedented stability to aperture masking, which should enable an order of magnitude better contrast than ground-based masking, in addition to a far lower thermal background. (click here for the abstract)

Reference: Greenbaum, A. G., Johns Hopkins University, Co-authors: Laurent Pueyo, Anand Sivaramakrishnan, Sylvestre Lacour, 2015, ApJ, 798, 68

Prospects for Characterizing Host Stars of the Planetary System Detections Predicted for the Korean Microlensing Telescope Network

Why JWST is important:-The Korean Microlensing Telescope Network will conduct an automated survey of the Galactic bulge beginning in 2016 to detect exoplanets via gravitational microlensing. It is expected to increase the detection rate of planets via microlensing by a factor of ~5 over current surveys. NIRCam on JWST will be able to constrain the NIR flux from the lensing systems for a significant fraction of these exoplanet detections using several different methods to obtain high-resolution photometry. This will allow for the precise measurement of the masses of these planets as well as the their host stars. (click here for the abstract)

Reference: Calen B. Henderson, The Ohio State University, Co-authors:- None, 2015, ApJ, 800, 58H

Detecting Industrial Pollution in the Atmospheres of Earth-like Exoplanets

Why JWST is important:- This study shows that with JWST spectroscopy, it is possible to constrain or detect anthropogenic pollution in the atmospheres of exoplanets.
(click here for the abstract)

Reference: Henry Lin, Harvard, Co-authors:- Gonzalo Gonzalez Abad and Abraham Loeb 2014, ApJ, 792, L7

Discriminating Between Cloudy, Hazy and Clearsky Exoplanets Using Refraction

Why JWST is important:- JWST will open up new possibilities for characterizing transiting exoplanets, and may provide the first platform for detecting refracted light in the out-of-transit lightcurve of an exoplanet. These observations cannot be made with existing telescopes and instruments because of the limited collecting area. However, JWST, with a collecting area much greater than that of the Hubble Space Telescope, will allow for more precise measurements to be made will make detections of refracted light possible within 10's of hours of telescope time for nearby exoplanets.
(click here for the abstract)

Reference: Amit Misra, University of Washington, Co-authors:- Victoria Meadows 2014, ApJ, 795L, 14M

Water Clouds in Y Dwarfs and Exoplanets

Why JWST is important:- In this paper, we modeled the spectra of Y dwarfs including water ice cloud opacity. We made predictions for the observability of Y dwarfs with JWST in the near- and mid-infrared. Figures 18 and 19 in the paper show the spectra of brown dwarfs from 200 to 450 K with predicted sensitivity limits for NIRSpec and MIRI.
(click here for the abstract)

Reference: Caroline Morley, University of California Santa Cruz, Co-authors:- Mark Marley, Jonathan Fortney, Roxana Lupu, Didier Saumon, Tom Greene, Katharina Lodders, 2014, ApJ, 787, 78M

Detectability of Free Floating Planets in Open Clusters with JWST

Why JWST is important:- The high contrast with the star for bounded planets poses very strict, and usually unmanageable, limits on their direct observation. On the contrary, the large population of free-floating planets predicted in this work might be detected with the next generation of space telescopes, given that their surface temperature is sufficiently high. Our study on observability shows that even with a relatively low-temperature planet at 300 K, a detection may be feasible in the infrared band, using the NIRcam instrument onboard the future JWST observatory. A clear detection becomes much more feasible if a fraction of free-floating planets reaches temperatures of at least 500 K.
(click here for the abstract)

Reference: Fabio Pacucci, Scuola Normale Superiore (Pisa, Italy), Co-authors:- Andrea Ferrara, Elena D'Onghia, 2013, ApJ, 778L, 42