Uploaded April 2025 | Updated September 2026, 2 weeks ago
Nick Tusay is part of the 2025 NASA ExoExplorers cohort, a program that aims to enable the professional development of graduate students and/or postdocs in exoplanet research (“ExoExplorers”).
The ExoExplorers program, sponsored by NASA’s Exoplanet Exploration Program Office and the ExoPAG Executive Committee, will focus on the professional development of ~10 graduate student and/or postdoc researchers (“ExoExplorers”) at US and international institutions. Each member of the cohort will be featured in a webinar that will be live-streamed to the exoplanet community, helping to increase their visibility within the field and build internal and external research networks. The cohort will also learn from the experiences of established exoplanet researchers and engineers in the field (“ExoGuides”) via a combination of tailored presentations and small group discussions.
Talk title: K2-22b: Measuring Exposed Hot Rock Entrails with JWST
Abstract: The disintegrating ultra-short period rocky exoplanet K2-22b periodically emits dusty clouds in a dynamically chaotic process resulting in a variable transit depth from 0-1.3%. The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface. Transmission spectroscopy of these transiting clouds reveal spectral fingerprints of the interior composition of this rocky world. We used JWST's Mid-Infrared Instrument (MIRI) as a low-resolution slitless spectrograph to observe four predicted transit windows for K2-22b. For each observation, we extracted a transmission spectrum over the spectral range of 4.3-11.8 μm. We detect one transit at high significance and two at low significance. We find that the data 1) disfavor featureless, iron-dominated core material, 2) are consistent with some form of magnesium silicate minerals, likely from mantle material, and 3) show a distinct and unexpected feature at ∼5 μm. The unexpected feature, also seen weakly in the low-significance transits, is consistent with some gas features, possibly NO and/or CO2. These findings warrant further study to improve the constraints on the composition of this disintegrating rocky world.
Nick Tusay is part of the 2025 NASA ExoExplorers cohort, a program that aims to enable the professional development of graduate students and/or postdocs in exoplanet research (“ExoExplorers”).
The ExoExplorers program, sponsored by NASA’s Exoplanet Exploration Program Office and the ExoPAG Executive Committee, will focus on the professional development of ~10 graduate student and/or postdoc researchers (“ExoExplorers”) at US and international institutions. Each member of the cohort will be featured in a webinar that will be live-streamed to the exoplanet community, helping to increase their visibility within the field and build internal and external research networks. The cohort will also learn from the experiences of established exoplanet researchers and engineers in the field (“ExoGuides”) via a combination of tailored presentations and small group discussions.
Talk title: K2-22b: Measuring Exposed Hot Rock Entrails with JWST
Abstract: The disintegrating ultra-short period rocky exoplanet K2-22b periodically emits dusty clouds in a dynamically chaotic process resulting in a variable transit depth from 0-1.3%. The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface. Transmission spectroscopy of these transiting clouds reveal spectral fingerprints of the interior composition of this rocky world. We used JWST's Mid-Infrared Instrument (MIRI) as a low-resolution slitless spectrograph to observe four predicted transit windows for K2-22b. For each observation, we extracted a transmission spectrum over the spectral range of 4.3-11.8 μm. We detect one transit at high significance and two at low significance. We find that the data 1) disfavor featureless, iron-dominated core material, 2) are consistent with some form of magnesium silicate minerals, likely from mantle material, and 3) show a distinct and unexpected feature at ∼5 μm. The unexpected feature, also seen weakly in the low-significance transits, is consistent with some gas features, possibly NO and/or CO2. These findings warrant further study to improve the constraints on the composition of this disintegrating rocky world.
