The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST

The Astronomical Journal, Год журнала: 2019, Номер 158(1), С. 27 - 27

Опубликована: Июнь 21, 2019

The James Webb Space Telescope (JWST) will offer the first opportunity to characterize terrestrial exoplanets with sufficient precision identify high mean molecular weight atmospheres, and TRAPPIST-1's seven known transiting Earth-sized planets are particularly favorable targets. To assist community preparations for JWST, we use simulations of plausible post-ocean-loss habitable environments TRAPPIST-1 exoplanets, test all bright object time series spectroscopy modes MIRI photometry filters determine optimal observing strategies atmospheric detection characterization using both transmission emission observations. We find that NIRSpec Prism is detecting terrestrial, CO2 containing potentially in fewer than 10 transits planets, if they lack altitude aerosols. If possess Venus-like H2SO4 aerosols, up 12 times more may be required detect atmospheres. present instruments individual species a given atmosphere an observational strategy discriminating between evolutionary states. water prohibitively difficult atmospheres due its presence lower where spectra less sensitive. Although biogenic O2 O3 extremely challenging detect, abiotically produced oxygen from past ocean loss detectable via O2-O2 collisionally-induced absorption at 1.06 1.27 microns, or NIR features outer three planets. Our results constitute suite hypotheses on nature detectability highly-evolved exoplanet tested JWST.

Язык: Английский

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Thermal emission from the Earth-sized exoplanet TRAPPIST-1 b using JWST

Nature, Год журнала: 2023, Номер 618(7963), С. 39 - 42

Опубликована: Март 27, 2023

Язык: Английский

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Revealing the Mysteries of Venus: The DAVINCI Mission

The Planetary Science Journal, Год журнала: 2022, Номер 3(5), С. 117 - 117

Опубликована: Май 1, 2022

The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission described herein has been selected for flight to as part the NASA Discovery Program. DAVINCI will be first incorporate science-driven flybys an instrumented descent sphere into a unified architecture. anticipated scientific outcome new understanding atmosphere, surface, evolutionary path possibly once-habitable planet analog hot terrestrial exoplanets. primary design features preferred launch in summer/fall 2029, two 2030, atmospheric entry by end 2031. situ phase subsequently delivers definitive chemical isotopic composition atmosphere during cloud-top surface transect above Alpha Regio. These investigations near infrared imaging complement remote flyby observations dynamic cloud deck, emissivity. overall yield at least 60 Gbits (compressed) data about well unique characterization deep environment chemistry, including trace key stable isotopes, oxygen fugacity, constraints on local rock compositions, topography tessera.

Язык: Английский

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No thick carbon dioxide atmosphere on the rocky exoplanet TRAPPIST-1 c

Nature, Год журнала: 2023, Номер 620(7975), С. 746 - 749

Опубликована: Июнь 19, 2023

Seven rocky planets orbit the nearby dwarf star TRAPPIST-1, providing a unique opportunity to search for atmospheres on small outside Solar System (Gillon et al., 2017). Thanks recent launch of JWST, possible atmospheric constituents such as carbon dioxide (CO2) are now detectable (Morley 2017, Lincowski 2018}. Recent JWST observations innermost planet TRAPPIST-1 b showed that it is most probably bare rock without any CO2 in its atmosphere (Greene 2023). Here we report detection thermal emission from dayside c with Mid-Infrared Instrument (MIRI) at 15 micron. We measure planet-to-star flux ratio fp/fs = 421 +/- 94 parts per million (ppm) which corresponds an inferred brightness temperature 380 31 K. This high disfavours thick, CO2-rich planet. The data rule out cloud-free O2/CO2 mixtures surface pressures ranging 10 bar (with ppm CO2) 0.1 (pure CO2). A Venus-analogue sulfuric acid clouds also disfavoured 2.6 sigma confidence. Thinner or bare-rock surfaces consistent our measured ratio. absence suggests relatively volatile-poor formation history, less than 9.5 +7.5 -2.3 Earth oceans water. If all system formed same way, this would indicate limited reservoir volatiles potentially habitable system.

Язык: Английский

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High Tide or Riptide on the Cosmic Shoreline? A Water-rich Atmosphere or Stellar Contamination for the Warm Super-Earth GJ 486b from JWST Observations

The Astrophysical Journal Letters, Год журнала: 2023, Номер 948(1), С. L11 - L11

Опубликована: Май 1, 2023

Planets orbiting M-dwarf stars are prime targets in the search for rocky exoplanet atmospheres. The small size of M dwarfs renders their planets exceptional transmission spectroscopy, facilitating atmospheric characterization. However, it remains unknown whether host stars' highly variable extreme-UV radiation environments allow atmospheres to persist. With JWST, we have begun determine or not most favorable worlds detectable Here, present a 2.8-5.2 micron JWST NIRSpec/G395H spectrum warm (700 K, 40.3x Earth's insolation) super-Earth GJ 486b (1.3 R$_{\oplus}$ and 3.0 M$_{\oplus}$). measured from our two transits deviates flat line at 2.2 - 3.3 $\sigma$, based on three independent reductions. Through combination forward retrieval models, that either has water-rich atmosphere (with stringent constraint retrieved water abundance H2O > 10% 2$\sigma$) is contaminated by cool unocculted starspots. We also find stellar best fit model with starspots hot faculae. While both scenarios provide equal quality fits ($\chi^2_\nu$ = 1.0) observations, shorter wavelength observations can break this degeneracy reveal if sustains atmosphere.

Язык: Английский

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Atmospheric Reconnaissance of TRAPPIST-1 b with JWST/NIRISS: Evidence for Strong Stellar Contamination in the Transmission Spectra

The Astrophysical Journal Letters, Год журнала: 2023, Номер 955(1), С. L22 - L22

Опубликована: Сен. 1, 2023

Abstract TRAPPIST-1 is a nearby system of seven Earth-sized, temperate, rocky exoplanets transiting Jupiter-sized M8.5V star, ideally suited for in-depth atmospheric studies. Each planet has been observed in transmission both from space and the ground, confidently rejecting cloud-free, hydrogen-rich atmospheres. Secondary eclipse observations b with JWST/MIRI are consistent little to no atmosphere given lack heat redistribution. Here we present first spectra obtained JWST/NIRISS over two visits. The show moderate strong evidence contamination unocculted stellar heterogeneities, which dominates signal spectrum visit starspots second exhibits signatures faculae. Fitting planetary either sequentially or simultaneously, confirm absence atmospheres, but cannot assess presence secondary We find that uncertainties associated model fidelity one order magnitude above observation precision 89 ppm (combining visits). Without affecting conclusion regarding b, this highlights an important caveat future explorations, calls additional characterize heterogeneities empirically and/or theoretical works improve such cool stars. This need all more justified as can affect search atmospheres around outer, cooler planets spectroscopy currently most efficient technique.

Язык: Английский

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JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b

The Astronomical Journal, Год журнала: 2024, Номер 167(3), С. 90 - 90

Опубликована: Фев. 5, 2024

Abstract We present a JWST/Near Infrared Camera (NIRCam) transmission spectrum from 3.9 to 5.0 μ m of the recently validated sub-Earth GJ 341b ( R P = 0.92 ⊕ , T eq 540 K) orbiting nearby bright M1 star d 10.4 pc, K mag 5.6). use three independent pipelines reduce data JWST visits and perform several tests check for significance an atmosphere. Overall, our analysis does not uncover evidence Our null hypothesis find that none pipelines’ spectra can rule out flat line, although there is weak Gaussian feature in two different (at 2.3 2.9 σ ). However, candidate features are seen at wavelengths (4.3 versus 4.7 m), retrieval finds gas species explain these reductions (CO 2 3.1 compared O 3 ), suggesting they real astrophysical signals. forward-model rules low-mean-molecular-weight atmosphere (<350× solar metallicity) least disfavors CH 4 -dominated atmospheres 1–3 depending on reduction. Instead, forward models consistent with no atmosphere, hazy or containing have prominent molecular bands across NIRCam/F444W bandpass, such as water-dominated results demonstrate unequivocal need more transit observations analyzed multiple reduction pipelines, alongside rigorous statistical tests, determine robustness detections small exoplanet atmospheres.

Язык: Английский

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Reliable Detections of Atmospheres on Rocky Exoplanets with Photometric JWST Phase Curves

The Astrophysical Journal Letters, Год журнала: 2025, Номер 978(2), С. L40 - L40

Опубликована: Янв. 9, 2025

Abstract The prevalence of atmospheres on rocky planets is one the major questions in exoplanet astronomy, but there are currently no published unambiguous detections any exoplanets. MIRI instrument JWST can measure thermal emission from tidally locked exoplanets orbiting small, cool stars. This a function their surface and atmospheric properties, potentially allowing atmospheres. One way to find search for lower dayside than would be expected blackbody planet. Another technique phase curves nightside due heat redistribution. Here, we compare strategies detecting We simulate secondary eclipse curve observations F1500W F1280W filters range surfaces (providing our open-access albedo data) 30 selected signal-to-noise ratio. show that more degenerate between suggested previous work, thick support consistent with planet these filters. These results make it difficult unambiguously detect or rule out using photometric alone. suggest an could instead observed similar sample planets. While time-consuming instrumental systematics challenging, they allow only by emission.

Язык: Английский

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Impact of Clouds and Hazes on the Simulated JWST Transmission Spectra of Habitable Zone Planets in the TRAPPIST-1 System

The Astrophysical Journal, Год журнала: 2019, Номер 887(2), С. 194 - 194

Опубликована: Дек. 19, 2019

Abstract The TRAPPIST-1 system, consisting of an ultracool host star having seven known Earth-sized planets, will be a prime target for atmospheric characterization with the James Webb Space Telescope ( JWST ). However, detectability molecular species may severely impacted by presence clouds and/or hazes. In this work, we perform 3D general circulation model (GCM) simulations LMD-G supplemented 1D photochemistry at terminator Atmos to simulate several possible atmospheres TRAPPIST-1e, 1f, and 1g: (1) modern Earth, (2) Archean (3) CO 2 -rich atmospheres. synthetic transit spectra were computed using GSFC Planetary Spectrum Generator. We find that 1g atmospheres, hazes, could detected ’s NIRSpec Prism from absorption line 4.3 μ m in less than 15 transits 3 σ or 35 5 . our analysis suggests other gases would require hundreds (or thousands) detectable. also H O, mostly confined lower atmosphere, is very challenging detect these planets similar systems if planets’ are not moist greenhouse state. This result demonstrates use GCMs, self-consistently taking into account effect subsaturation, crucial evaluate molecules interest, as well interpreting future detections more global (and thus robust relevant) approach.

Язык: Английский

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A Comparative Study of Atmospheric Chemistry with VULCAN

The Astrophysical Journal, Год журнала: 2021, Номер 923(2), С. 264 - 264

Опубликована: Дек. 1, 2021

Abstract We present an update of the open-source photochemical kinetics code VULCAN to include C–H–N–O–S networks and photochemistry. The additional new features are advection transport, condensation, various boundary conditions, temperature-dependent UV cross sections. First, we validate our model for hot Jupiter atmospheres by performing intercomparison HD 189733b models between Moses et al., Venot VULCAN, diagnose possible sources discrepancy. Second, set up a extending from deep troposphere upper stratosphere verify low temperature. Our reproduces hydrocarbons consistent with observations, condensation scheme successfully predicts locations water ammonia ice clouds. show that vertical can regulate local distribution in atmosphere. Third, oxidizing simulating Earth find agreement observations. Last, is applied four representative cases extrasolar giant planets: WASP-33b, 189733b, GJ 436b, 51 Eridani b. look into effects C/O ratio chemistry titanium/vanadium species revisit sulfur carbon internal heating mixing ( K zz ) explored test updated planetary properties b S 8 condensates. couple or nitrogen impact other species, such as hydrogen, methane, ammonia. observable synthetic spectra trends haze precursors discussed each case.

Язык: Английский

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