WASP-39 b Archives

Artistic representation of WASP-94 A b. Clouds build as air flows over the dark side of the planet, reaching a large swell by daybreak. The clouds dissipate on the dayside, leaving clear skies in the early evening. Image courtesy of Hannah Robbins/Johns Hopkins University

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Astronomers Observe Exoplanet Atmospheres With New Cloud-detecting Method

by Keith CowingMay 22, 2026May 22, 2026

Every morning, clouds roll in, and by evening, they have cleared off. This sounds like a weather forecast for a coastal city here on Earth — but it’s for WASP-94A […]

Mg/Si ratios of JWST-observed hot Jupiter host stars versus separation (semi-major axis).

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Imaging & Spectroscopy, Status Report

Bridging the Gap: Using Brown Dwarfs to Examine Silicate Clouds in Giant Exoplanet Atmospheres

by Keith CowingMarch 17, 2026March 17, 2026

We present results from examining the silicate cloud modeling of four JWST-observed hot Jupiters in the context of brown dwarf theory to further explore signatures of formation in present-day atmospheres.

Calculated vertical distribution of abundances for the warm Neptunes GJ 436b and GJ 1214b. The solid lines correspond to the mean abundance, the shaded areas to the range around the mean ±σ, and the dotted lines to the abundances resulting from the unperturbed model. The panels on the left show the effect on the calculated abundances of the uncertainties on (photo)chemical kinetics, while the right panels correspond to the effect on the abundances of the uncertainty in Kzz. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Quantification Of Abundance Uncertainties In Chemical Models Of Exoplanet Atmospheres

by Keith CowingDecember 4, 2025December 4, 2025

Chemical models are routinely used to predict the atmospheric composition of exoplanets and compare it with the composition retrieved from observations, but little is known about the reliability of the […]

Retrievals of Cassini/VIMS occultation of Titan. Top left: observations and best-fit TauREx retrievals. Bottom left: breakdown of the extinction contributions in the tholin + CH4(l)(HITRAN) case. Right: Atmospheric properties inferred for the tholin + CH4(l) (HITRAN) case. The source for the opacity data (i.e, HITRAN or ExoMol) is important and can slightly change the best-fit spectrum and retrieval interpretation. Overall, the Cassini data is dominated by molecular absorption from CH4, CO, C2H6, C3H8 and extinction by hydrocarbon aerosols (tholins + CHCH4(l). The shape of the 3.4 µm absorption feature is likely best explained by the contribution of multiple species including some contribution from tholins. Overall, retrieval interpretations of Titan’s atmosphere are compatible with stratospheric inferences from previous works (see Figure B1). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Titan

Cloud and Haze Parameterization in Atmospheric Retrievals: Insights from Titan’s Cassini Data and JWST Observations of Hot Jupiters

by Keith CowingMay 27, 2025May 27, 2025

Context: Before JWST, telescope observations were not sensitive enough to constrain the nature of clouds in exo-atmospheres. Recent observations, however, have inferred cloud signatures as well as haze-enhanced scattering slopes […]

The retrieved spectra using the hybrid equilibrium chemistry model and machine learning approaches are shown. Observations from JWST instruments are illustrated with different colored error bars: green for NIRISS, blue for NIRSpec PRISM, and golden for MIRI. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

A Next-Generation Exoplanet Atmospheric Retrieval Framework for Transmission Spectroscopy (NEXOTRANS): Comparative Characterization for WASP-39 b Using JWST NIRISS, NIRSpec PRISM, and MIRI Observations

by Keith CowingMay 2, 2025May 2, 2025

The advent of JWST has marked a new era in exoplanetary atmospheric studies, offering higher-resolution data and greater precision across a broader spectral range than previous space-based telescopes.

Patterns of atmospheric asymmetry and their different impacts on light curves. The blue solid lines and grey dashed lines in the figures on the right of each panel correspond to the light curves of the blue and grey disks of the planet’s shadow in the schematics on the left, respectively. (a) A displacement of the planet’s shadow along the X–axis (morning-evening asymmetry) causes a shift of the central transit time t0. (b) A displacement along the Y –axis (north-south asymmetry) causes a change in the transit duration. (c) Opposite displacements along the X–axis between ingress and egress also alter the transit duration. (d) Changes in the apparent radius result in variations in both the transit depth and duration. In Panel (d), the radius of the blue disk is exaggerated by a factor of 5 compared to the disk producing the blue light curve, to highlight the differences between the grey and blue disks. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Probing 2D Asymmetries Of An Exoplanet Atmosphere From Chromatic Transit Variation

by Keith CowingMarch 17, 2025September 18, 2025

We propose a new method for investigating atmospheric inhomogeneities in exoplanets through transmission spectroscopy. Our approach links chromatic variations in conventional transit model parameters (central transit time, total and full […]

This artist’s concept shows what the exoplanet WASP-39 b could look like based on indirect transit observations from NASA’s James Webb Space Telescope as well as other space- and ground-based telescopes. Data collected by Webb’s NIRSpec (Near-Infrared Spectrograph) show variations between the eternal morning and evening atmosphere of the planet. -- NASA, ESA, CSA, R. Crawford (STScI)

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release

Webb Investigates Sunrises And Sunsets On Distant World WASP-39 b

by Keith CowingOctober 21, 2024October 21, 2024

Researchers using NASA’s James Webb Space Telescope have finally confirmed what models have previously predicted: An exoplanet has differences between its eternal morning and eternal evening atmosphere.

Top: The high-resolution spectrum of the T-dwarf Gl229 B analyzed using ExoJAX2 (Kawashima et al. submitted) with ∼ 108 total molecular absorption lines considered. The blue solid line shows the median value, while the blue shaded regions indicate the 95% credible interval. Black points represent the observed Subaru/IRD data. The periodic increases in the residuals observed correspond to the gaps between orders. Bottom: Medium-resolution transmission spectrum of WASP-39 b analyzed using ExoJAX2 and the HMC-NUTS method. The black solid line represents the model derived from the median values of each parameter obtained through MCMC sampling, with the 95% credible interval shaded in gray. The blue points show the observed planetary radii from JWST NIRSpec/G395H observations. The vertical axis on the left shows the planetary radius, while the vertical axis on the right displays the corresponding pressure. The contributions of CO, CO2, H2O, SO2, gray clouds, and collision-induced absorption (CIA) are represented by colored shading with an offset of -0.01 Rs. -- astro-ph.SR

AI - Data - Apps - Cybernetics, Apps - Games, Astronomy & Telescopes, Brown Dwarfs, Imaging & Spectroscopy, Status Report, Stellar Cartography

Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2

by Keith CowingOctober 10, 2024October 10, 2024

Modeling based on differentiable programming holds great promise for astronomy, as it can employ techniques such as Hamiltonian Monte Carlo, gradient-based optimization, and other machine learning techniques.

The best fits to the excess flux as calculated from the transmission spectrum (top) or from the stellar spectrum (bottom). We fit a crystalline silicate feature and a blackbody curve to both spectra separately. These plots assume the 3σ upperlimit to the WISE/W4 flux. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Debris Disks can Contaminate Mid-Infrared Exoplanet Spectra: Evidence for a Circumstellar Debris Disk around Exoplanet Host WASP-39

by Keith CowingJune 11, 2024June 11, 2024

The signal from a transiting planet can be diluted by astrophysical contamination. In the case of circumstellar debris disks, this contamination could start in the mid-infrared and vary as a […]

The combined STIS G430L and G750L spectrum of WASP-39 b (top left), WASP-121 b (top right), WASP-69 b (bottom left), and WASP-17 b (bottom right). Each color (common between planets) corresponds to a different systematics detrending technique, either using linear or GP methods and either between 1-10 PCs or the 10 initial input vectors. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Stellar Cartography

HST SHEL: Enabling Comparative Exoplanetology with HST/STIS

by Keith CowingJune 3, 2024

The Hubble Space Telescope (HST) has been our most prolific tool to study exoplanet atmospheres. As the age of JWST begins, there is a wealth of HST archival data that […]

WASP-39 b

Astronomers Observe Exoplanet Atmospheres With New Cloud-detecting Method

Bridging the Gap: Using Brown Dwarfs to Examine Silicate Clouds in Giant Exoplanet Atmospheres

Quantification Of Abundance Uncertainties In Chemical Models Of Exoplanet Atmospheres

A Next-Generation Exoplanet Atmospheric Retrieval Framework for Transmission Spectroscopy (NEXOTRANS): Comparative Characterization for WASP-39 b Using JWST NIRISS, NIRSpec PRISM, and MIRI Observations

Probing 2D Asymmetries Of An Exoplanet Atmosphere From Chromatic Transit Variation

Webb Investigates Sunrises And Sunsets On Distant World WASP-39 b

Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2

Debris Disks can Contaminate Mid-Infrared Exoplanet Spectra: Evidence for a Circumstellar Debris Disk around Exoplanet Host WASP-39

HST SHEL: Enabling Comparative Exoplanetology with HST/STIS

Alien World Chemistry Found Inside A Meteorite that Struck A New Jersey Home

Exoplanet Beta Pictoris d Found After More Than 10 Years Of Searching

When Stabilizing Feedbacks Wreak Havoc In Habitable Planets: Chaos At The Freezing Point In A Four-Feedback Climate Model

Biosignature Detectability On Transiting Habitable Worlds With ELT/ANDES

Rising From The Fragments: A Multi-factorial Regulatory Framework Of DNA Damage Response In Deinococcus radiodurans