gas giant Archives - Page 5 of 13 - Astrobiology

Cheops open questions: How do planets form?

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Press Release, Stellar Cartography

Cheops Discovers Late Bloomer Planet From Another Era

by Keith CowingFebruary 13, 2026February 13, 2026

Many Vile Earthlings Munch Jam Sandwiches Under Newspapers and My Very Educated Mother Just Served Us Nachos. What sounds like gibberish half-sentences are memory aids taught to children to help […]

Schematic of some of the key processes throughout planet formation that influence carbon supply and retention. (a) Key ice/grain sublimation fronts in the disk noted (CO2 between water–CO and that of Silicates at inner disk edge not shown). Planets forming in these locations will receive different compositions at birth (Öberg et al. 2011). Dust that grows beyond the “soot” line (Lodders 2004, Kress et al. 2010, Li et al. 2021) will be rich in refractory carbon content and at greater distances molecular ices. (blow-out:) The drift of carbon-rich pebbles from the outer disk is a key process in carbon supply. Drift itself is influenced by pressure bumps that can lead to a pile-up of pebbles that can be potential sites for planetesimal and planet formation (shown on left side of disk). (b) Solids accrete ice mantles, sublimate key components at sublimation fronts and can collide leading to both growth and fragmentation. (c) Rocky planets and cores of gas-rich planets grow and gain carbon through accretion of pebbles (top) and/or planetesimals (bottom). Impacts of larger planetesimals can also strip atmospheric gas and also supply material. (d) heavy element differentiation can take carbon to the core, and the resulting magma ocean/atmosphere equilibrium can influence atmospheric composition with lighter gases escaping depending on the planet mass. Figure credit to N. Fuller and Sayo Studio. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Press Release

Carbon From Interstellar Clouds To Habitable Worlds

by Keith CowingFebruary 12, 2026February 12, 2026

Carbon is an essential element for a habitable world. Inner (r < 3 au) disk planetary carbon compositions are strongly influenced by supply and survival of carbonaceous solids. Here we […]

Time-lapse footage of a newly discovered exoplanet as it makes its slow journey around two stars. To obtain the image of the planet, astronomers needed to remove the stars' glare. Two star icons mark the locations of where the stars would be in relation to their planet. Credit Jason Wang/Northwestern University

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release, Science Fiction

Rare Image Of Tatooine-like Planet Is Closest To Its Twin Stars Yet

by Keith CowingDecember 14, 2025December 14, 2025

In a discovery that’s fit for a movie, Northwestern University astronomers have directly imaged a Tatooine-like exoplanet, orbiting two suns.

Image of HIP 71618 B (indicated by the arrow) taken by the Subaru Telescope. The planet’s host star has been blocked in this image. The star’s position is indicated by the star mark. The high resolution image and the image without text are available from the links. (Credit: T. Currie/Subaru Telescope, UTSA)

AI - Data - Apps - Cybernetics, Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

First Results From The Subaru Telescope’s OASIS Survey: Direct Imaging Of New Worlds Around Unexplored Stars

by Keith CowingDecember 7, 2025December 7, 2025

The discovery of two remarkable substellar companions orbiting distant stars has been announced by an international team of astronomers using the Subaru Telescope’s sharp adaptive-optics imaging together with precision stellar […]

Top: Maximum A Posteriori (MAP) model and 2σ credible regions from ExoTR retrievals on the fiducial reduction, overlaid with data binned at ∆λ = 0.05 µm. Also shown are the contributions from each molecule and clouds to the transmission spectrum. Bottom: 1D histograms of the posterior distributions from the retrieval results, including the median and ±1σ uncertainties (i.e. 16th and 84th percentiles).-- astro-ph.EP

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Status Report

Methane On The Temperate Exo-Saturn TOI-199b

by Keith CowingNovember 28, 2025November 28, 2025

Temperate (Teq<400 K) gas giants represent an unexplored frontier in exoplanet atmospheric spectroscopy. Orbiting a G-type star every ~100 days, the Saturn-mass exoplanet TOI-199 b (Teq=350 K) is one of […]

The three-layer diagram of the outcome of our model.

Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Press Release

Efficiency of Hydrodynamic Atmospheric Escape in Hot Jupiters and Super Earths

by Keith CowingNovember 27, 2025November 27, 2025

We develop a flexible one-dimensional code to model the escape of hydrogen and helium from a hot Jupiter as a result of photoionization from extreme-ultraviolet (EUV) radiation.

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 […]

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

Tidally Torn: Why the Most Common Stars May Lack Large, Habitable-Zone Moons

by Keith CowingNovember 9, 2025

Earth-like planets in the habitable zone (HZ) of M-dwarfs have recently been targeted in the search for exomoons.