Gas Giants Archives

Contours for the ratio rH/rT of the two radii of circumplanetary disk. The red dashed line denotes the ratio rH/rT = 1. The area to the right of the red dashed line with rH/rT > 1 is favourable for moon’s survival and the area to the left with rH/rT < 1 is unfavourable for moon’s survival. -- astro-ph.EP

Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Magnetic Fields, Electromagnetism, bioelectricity,, Status Report

Magnetic Field Of Gas Giant Exoplanets And Its Influence On The Retention Of Their Exomoons

by Keith CowingFebruary 13, 2024February 13, 2024

We study the magnetic and tidal interactions of a gas-giant exoplanet with its host star and with its exomoons, and focus on their retention. We briefly revisit the scaling law […]

Artistic representation of an exoplanet whose water ice on the surface is increasingly vaporizing and forming an atmosphere during its approach to the central star of the planetary system. This process increases the measured planetary radius compared to the value the planet would have at its place of origin. CREDIT Thomas Müller (MPIA)

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Press Release, Water/Hycean Worlds & Oceanography

Migration Solves An Exoplanet Puzzle

by Keith CowingFebruary 9, 2024February 9, 2024

Ordinarily, planets in evolved planetary systems, such as the Solar System, follow stable orbits around their central star. However, many indications suggest that some planets might depart from their birthplaces […]

Maps of the wavelength dependent optical depth (on a log scale), with optical depths of 0.1, 1.0 and 10 indicated by dotted/solid/dashed line respectively. We compare the optical depth profiles for an R=10 km, ρ =2 g cm−3 , JWST Ice ver. A cometary composition impact at three different points in time, 1 year (A), 5 years (C), and 25 years (C - steady-state) after impact, with our unperturbed HD209458b reference model (D). To emphasise how the opacity of the atmosphere varies time we also include, on our steady-state opacity map, the 1 year (green), 5 year (blue), 25 year (red) and reference (orange) τ = 1 surfaces as light shading. Note the significant effect that the addition of cometary material has had on the optical depth, in particular how an optical depth of one is reached at lower pressures, averaging ∼ 10−2 bar at steady-state vs ∼ 10−1 bar in the unperturbed model, helping to explain the difference in the transmission spectra seen in Figure 8. -- astro-ph.EP

Comets and Asteroids, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Impact events, Jupiter, Status Report

The Impact Of Cometary Impacts On The Chemistry, Climate, And Spectra Of Hot Jupiter Atmospheres

by Keith CowingFebruary 9, 2024February 9, 2024

Impacts from icy and rocky bodies have helped shape the composition of solar system objects, for example the Earth-Moon system, or the recent impact of comet Shoemaker-Levy 9 with Jupiter. […]

Green triangles show an estimate of the heavyelement content (MZ ) of GEMS from planetary interior models (Thorngren et al. 2016) compared to the Class II disk dust mass (Md) estimates as orange squares (Manara et al. 2022) and the median (and 1-σ) trend seen in the Lupus sample (Ansdell et al. 2016). The green arrows show the approximate expected disk dust masses required to form the green triangles assuming 10% formation efficiency (Liu et al. 2019b). The red line shows the range of dust masses for Class 0 and I disks from Tychoniec et al. (2020). Takeaway: The formation of GEMS necessitates disks with many 100s of M⊕ of heavy-elements. This could be achieved by anomalously massive Class II disks with underestimated dust masses, or Class 0/I disks. -- astro-ph.EP

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

Searching For Giant Exoplanets Around M-dwarf Stars (GEMS) I: Survey Motivation

by Keith CowingFebruary 9, 2024February 9, 2024

Recent discoveries of transiting giant exoplanets around M-dwarf stars (GEMS), aided by the all-sky coverage of TESS, are starting to stretch theories of planet formation through the core-accretion scenario. Recent […]

Distribution of eccentricities for all planets more massive than 0.3 MJ interior to the snow line (left panels) and exterior to the snow line (right panels). For the top two panels, both the shade and the size of the plotted data are logarithmically proportional to the planet mass, where dark green indicates a low mass and light green indicates a high mass. The bottom two panels show the histograms of the eccentricity data appearing in the top two panels. -- astro-ph.EP

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Eccentricity Distribution Beyond the Snow Line and Implications for Planetary Habitability

by Keith CowingFebruary 7, 2024February 7, 2024

A fundamental question in the study of planetary system demographics is: how common is the solar system architecture?

Inferred reflectance and temperature maps for each planet, where the center of the map corresponds to the sub-stellar point. The shading in the upper row corresponds to the single scattering albedo ω of the reflective region on the dayside. Cross validation prefers inhomogeneous models for each planet, so each dayside features a dark sub-stellar region bounded by sub-observer longitudes x1 and x2. The thermal emission maps in the second row are not uniform, but appear nearly uniform in this figure because the colormap spans the full range of dayside temperatures for all five planets. -- astro-ph.EP

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

Observations Of Scattered Light From Exoplanet Atmospheres

by Keith CowingJanuary 26, 2024January 26, 2024

Optical phase curves of hot Jupiters can reveal global scattering properties. We implement a Bayesian inference framework for optical phase curves with flux contributions from: reflected light from a potentially […]

Schematic diagram of various outcomes of planet formation when we assume efficient planet formation at pressure bumps. This diagram summarizes the results from Section 2.1 and 3.1. Pressure bumps allow planets to form quickly and at very similar time and location, which leads to pairs or chains of planets with highly similar masses. This leads to intra-similar “SuperEarths” and “Jupiters” whose masses are set by the pebble isolation mass and gas saturation mass, respectively. Meanwhile, planets that form cores slowly (“Earths”) or accrete massive envelopes slowly (“Saturns”) would exhibit less intra-system mass uniformity. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Jupiter, Saturn, Status Report

Earths Are Not Super-Earths, Saturns Are Not Jupiters: Imprints Of Pressure-bump Planet Formation On Planetary Architectures

by Keith CowingJanuary 14, 2024January 14, 2024

In protoplanetary disks, sufficiently massive planets excite pressure bumps, which can then be preferred locations for forming new planet cores. We discuss how this loop may affect the architecture of […]

SCT-determined column-averaged ammonia mole fraction in the GRS region separated by one week in time. Top: 2022-10-13 03:45UT; bottom: 2022-10-20 04:40UT. Large scale features persist, but smaller scale features show changes. While these changes may be physical, they may also represent indications of noise. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Jupiter, Status Report

Spatial Variations of Jovian Tropospheric Ammonia via Ground-Based Imaging

by Keith CowingDecember 27, 2023December 27, 2023

Optical bandpass-filter observations can be simply processed to determine similar horizontal ammonia distributions above the Jovian cloud tops as mid-infrared and microwave observations.