Gas Giants Archives

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Imaging & Spectroscopy, Status Report

A JWST Transit Of A Jupiter Analog: II. A Search For Exomoons

by Keith CowingNovember 22, 2025June 10, 2026

We present a search for exomoons around the Jupiter-like exoplanet Kepler-167e using a NIRSpec JWST transit.

Azimuthally averaged gas density (left) and gas radial velocity relative to the planet (right) for our FARGO3D disk model containing a Jupiter mass planet at 75 au. The CO sublimation surface at 30 K recovered from our RADMC-3D model is indicated in both panels by the red dashed line. The region near the embedded planet is heated from a combination of accretion heating onto the planet, disk viscous heating, and radiative heating from the star, resulting in higher temperatures at the midplane in the gap. Gas advection relative to the local sound speed is also indicated by white arrows. Gas advection is primarily outward along the midplane near the planet, with significant vertical flows away from the midplane at the gap edge and in the pressure bump at 100 au. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Dust Recycling and Icy Volatile Delivery (DRIVE): A Novel Method of Volatile Enrichment in Cold Giant Planets

by Keith CowingNovember 13, 2025November 13, 2025

Giant planet atmospheres are thought to reflect the gas phase composition of the disk when and where they formed.

Model spectra (top) and Kp-voffset maps for the combination of all nights (bottom) of H2O, H2S, and CH4 for KELT-11 b. The grey shaded areas show the wavelength regions of the spectral orders used for the analysis. The dotted lines indicate the expected location of the planetary signal. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

Upper Limits On Atmospheric Abundances Of KELT-11b And WASP-69b From A Retrieval Approach

by Keith CowingNovember 11, 2025November 11, 2025

WASP-69b and KELT-11b are two low-density hot Jupiters, which are expected to show strong atmospheric features in their transmission spectra.

Self-consistent obliquity and spin rate evolution for several realizations of exoplanet Kepler-79 d. Trajectories go from right to left. The planet is initalized with a spin rate of 7.5 hours (i.e. ω/np ≈ 170) and different obliquities equispaced in cos θ. A moon with mass mm/mp = 10−6 is initialized at a distance am = 4 Rp. Integrations are stopped when the moon’s pericenter goes below the Roche limit. The three largest resonances reacheable by Kepler-79 d appear in red, blue, and green. The hatched blue zone is the E1 region. For definitiveness, the resonances and E1 region in the background are drawn assuming that the moon is on a circular orbit at am = 4 Rp; for moons that do not cross the E1 region, this remains approximatively true during the whole simulation. -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Status Report, Stellar Cartography

The Coupled Tidal Evolution of the Moons and Spins of Warm Exoplanets

by Keith CowingNovember 10, 2025

Context: The Solar System giant planets harbour a wide variety of moons. Moons around exoplanets are plausibly similarly abundant, even though most of them are likely too small to be […]

Top: Blended MIRI LRS variability map of WISE J1049 AB: wavelength (x-axis) vs. time (y-axis) and normalized flux (amplitude; colorbar). There are two distinct lightcurve behaviors present, allowing for the construction of two unique lightcurves distinguished by the change in behavior at 8.5 µm (center dashed line). Bottom: Lightcurves 1 (red) and 2 (blue) constructed from the above data and outlined with an ∼ 11.77 min running median. -- astro-ph.EP

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

Sensitivity to Sub-Io-sized Exosatellite Transits In The MIRI LRS Lightcurve Of The Nearest Substellar Worlds

by Keith CowingNovember 7, 2025November 7, 2025

JWST’s unprecedented sensitivity enables precise spectrophotometric monitoring of substellar worlds, revealing atmospheric variability driven by mechanisms operating across different pressure levels.

Mean group (left), histograms of grouping across several MCMC samples

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Status Report

Horizontal And Vertical Exoplanet Thermal Structure From A JWST Spectroscopic Eclipse Map

by Keith CowingNovember 7, 2025November 7, 2025

Highly-irradiated giant exoplanets known as “ultra-hot Jupiters” are anticipated to exhibit large variations of atmospheric temperature and chemistry as a function of longitude, latitude, and altitude.

The four giant planets as seen by Hubble WFC3/UVIS at different near-UV wavelengths, and processed by Judy Schmidt (note - these images are not shown to scale). The Jupiter and Saturn images are constructed from F343N (red), F275W (green), and F225 (blue), whereas a lack of observations for Uranus and Neptune required us to shift to redder wavelengths: F547M (red), F467M (green), and F336W (blue) for the Ice Giants. Jupiter and Ganymede were observed 2017-02-02 at 12:16UT, Saturn was observed at 2018-06-07 at 00:06UT, Uranus on 2015-08-30 at 10:08UT, and Neptune on 2015-09-02 at 07:58UT. Strong UV absorption is visible at the poles of Jupiter and Saturn due to the nature of highaltitude aerosols and the potential link to auroral chemistry. Red vortices, such as Jupiter’s Great Red Spot and Oval BA (lower left), appear dark due to the blue-absorbing chromophore responsible for their red colours. Uranus’ bright north polar cap of aerosols, and its narrow rings, are just visible in this image. Neptune’s banding, and some bright high clouds (appearing in pink) can be seen in both northern and southern hemispheres. In addition, Saturn’s rings appear reddish due to UV absorption. Credit: NASA/ESA/CSA/Hubble/Judy Schmidt.

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Imaging & Spectroscopy, Jupiter, Neptune, Saturn, Status Report, Uranus

Exploring Giant Planet Atmospheres with Habitable Worlds Observatory

by Keith CowingOctober 22, 2025October 22, 2025

Visible and ultraviolet imaging and spectroscopy of Solar System giant planets can set the paradigm for the atmospheric, ionospheric, and magnetospheric processes shaping the diversity of giant exoplanets, brown dwarfs, […]

Schematic showing the reset approach applied for the close-in four-planet system. The left graphic shows “exaggerated” orbits of the four planets after the encounter when they are on slightly eccentric, non-coplanar orbits with the giant planet outside the axis limits. Note: In our simulations, none of the planets show this amount of perturbation at the reset at 1 Myr. On the right graphic after the reset, the four-planet system is set back to its original circular, coplanar orbits, but the giant planet’s orbit remains unchanged, being eccentric and/or inclined as shown in Fig. 2. The inner planet system is reset to its initial inclination at the start of the simulations to isolate the effect of internal perturbations after 500 Myr. -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Gas Giants, Status Report

The Impact Of Internal Versus External Perturbations On Close-in Exoplanet Architectures

by Keith CowingOctober 10, 2025October 10, 2025

Young planetary systems are subjected to different dynamical effects that can influence their orbital structure over time.

Periodograms of the raw RV time series (top panel) as well as of the residuals after subtracting the OGP (middle panel) and the ILP (bottom panel), for HD 23079 (left), HD 196067 (center), and HD 86226 (right). -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Status Report

Architecture Of Planetary Systems With And Without Outer Giant Planets I. Inner planet Detections Around HD 23079, HD 196067, And HD 86226

by Keith CowingOctober 5, 2025

Understanding the link between outer giant planets (OGPs) and inner light planets (ILPs) is key to understanding planetary system formation and architecture.

Alpha Centauri, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Imaging & Spectroscopy, Status Report, Stellar Cartography

Seeking The Worlds Of Avatar: Prospects for Detecting Moons Orbiting a Giant Planet in Alpha Centauri A’s Habitable Zone

by Keith CowingSeptember 22, 2025September 22, 2025

Nearby giant exoplanets offer an opportunity to search for moons (exomoons) orbiting them. Here, we present a simulation framework for investigating the possibilities of detecting exomoons via their astrometric signal […]

Gas Giants

A JWST Transit Of A Jupiter Analog: II. A Search For Exomoons

Dust Recycling and Icy Volatile Delivery (DRIVE): A Novel Method of Volatile Enrichment in Cold Giant Planets

Upper Limits On Atmospheric Abundances Of KELT-11b And WASP-69b From A Retrieval Approach

The Coupled Tidal Evolution of the Moons and Spins of Warm Exoplanets

Sensitivity to Sub-Io-sized Exosatellite Transits In The MIRI LRS Lightcurve Of The Nearest Substellar Worlds

Horizontal And Vertical Exoplanet Thermal Structure From A JWST Spectroscopic Eclipse Map

Exploring Giant Planet Atmospheres with Habitable Worlds Observatory

The Impact Of Internal Versus External Perturbations On Close-in Exoplanet Architectures

Architecture Of Planetary Systems With And Without Outer Giant Planets I. Inner planet Detections Around HD 23079, HD 196067, And HD 86226

Seeking The Worlds Of Avatar: Prospects for Detecting Moons Orbiting a Giant Planet in Alpha Centauri A’s Habitable Zone

Tricorder Tech: Ground Truth For The DAVINCI Venus Mission

Mars Curiosity Rover Finds Evidence Of An Ancient Sandstorm

Pristine Meteorite Examination Adds To Our Knowledge Of Ancient Asteroids

NASA Study Finds Near-Earth Asteroid Is Actually Comet

NASA Awards STRIDE Contracts For Mars Advanced Surface Mobility Technology