Gas Giants Archives

Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

Fresh View Of The Hot Brown Dwarf HD 984 B Through High-resolution Spectroscopy

by Keith CowingApril 20, 2024

Context. High-resolution spectroscopy has the potential to drive a better understanding of the atmospheric composition, physics, and dynamics of young exoplanets and brown dwarfs, bringing clear insights into the formation […]

Different scenarios of super-rotating atmospheric material. Panels a, b and c show the scenario of a homogeneously rotating planet. The purple solid line shows the velocity kernel of the material at rotation consistent with tidally locked rotation (panel b) and the resulting shape of the cross-correlation function (panel c). The turquoise dashed line shows the effect of the planet rotating approximately six times faster. Panels d, e and f show two cases of a super-rotating equatorial jet, with the poles rotating at tidally locked velocities. The difference between the two cases is the opening angle of the equatorial region (35◦ orange dashed, and 65◦ solid green). Panels g, h and i explore the case of the velocity kernel of a super-rotating equatorial jet (blue and red solid lines in panel h) with the polar region represented by the velocity kernel of super-rotating velocity (grey dash-dotted line) or tidally locked velocity (grey dotted line) but not contributing to the transmission spectrum due to muted atmospheric features, leading in both cases to only two peaks in the CCF (panel i). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

CRIRES+ Transmission Spectroscopy of WASP-127b. Detection Of The Resolved Signatures Of A Supersonic Equatorial Jet And Cool Poles In A Hot Planet

by Keith CowingApril 20, 2024April 20, 2024

General circulation models of gas giant exoplanets predict equatorial jets that drive inhomogeneities across the planetary atmosphere. We studied the transmission spectrum of the hot Jupiter WASP-127b during one transit […]

Overview of our samples. (a): the distribution of orbital period and stellar mass(p-𝑀∗) of all samples, the colors denote the equilibrium temperature of each giant planet (from blue to red corresponds to 100 K to 4000K, where pink dotted line and dark blue dotted line mark the position of 0.1𝑎snow and 1.0𝑎snow of different host stars; (b): the distribution of planetary mass and effective temperature of host star( 𝑚p-𝑇eff) of our giant planets samples, detection completeness shown as color contours from 0.0 to 1.0 in steps of 0.1. -- astro-ph.EP

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

Mutual Occurrence Ratio of Planets. I. New Clues to Reveal Origins of Hot- and Warm-Jupiter from the RV Sample

by Keith CowingApril 20, 2024April 20, 2024

Many studies have analyzed planetary occurrence rates and their dependence on the host’s properties to provide clues to planet formation, but few have focused on the mutual occurrence ratio of […]

The contribution functions for W1935 and W2220 maximum likelihood retrieval models. The CH4 emission seen in W1935 originates from pressures shallower than 0.01 bar. -- astro-ph.SR

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

Methane Emission From a Cool Brown Dwarf

by Keith CowingApril 20, 2024

Beyond our solar system, aurorae have been inferred from radio observations of isolated brown dwarfs (e.g. Hallinan et al. 2006; Kao et al. 2023). Within our solar system, giant planets […]

Emblematic direct imaging discoveries (not exhaustive): 2M1207 & AB Pic [24,25], RXJ 1609 [26], κ And [27], HR 8799 [28], β Pic [29], HD 95086 b [30], GJ 504 [31], 51 Eri b [32], HIP 65426 b [33], TYC 8998-760-1 b [34], and b Cen b [35]. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography

Direct Imaging Of Exoplanets: Legacy And Prospects

by Keith CowingApril 18, 2024

Understanding how giant and terrestrial planets form and evolve, what is their internal structure and that of their atmosphere, represents one of the major challenges of modern astronomy, which is […]

Schematic diagram of our preferred scenario. Red circles are planetesimals (and their fragments) from the terrestrial planet region. The black solid curves roughly denote the boundary of the current asteroid inner main belt. Eccentricity increases from bottom to top. Each panel shows the proposed evolution of the inner Solar System at different time ranges: (A) Formation and cooling of the EL planetesimal in the terrestrial planet region before 60 Myr after Solar System formation. In this period, the terrestrial planets began scattering planetesimals to orbits with high eccentricity and semimajor axes that correspond to the asteroid main belt. (B) Between 60 and 100 Myr, the EL planetesimal was destroyed by an impact in the terrestrial planet region. At least one fragment (the Athor family progenitor) was scattered by the terrestrial planets into the scattered disk, as in (A), then the giant planet instability implanted it into the inner main belt by decreasing its eccentricity. (C) A few tens of millions of years after the giant planet instability occurred, a giant impact between the planetary embryo Theia and proto-Earth formed the Moon. (D) The Athor family progenitor experienced another impact event that formed the Athor family at ~1500 Myr. -- Science

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Gas Giants, Meteorites & Asteroids, Press Release

Dating The Solar System’s Giant Planet Migration Using Chondrite Meteorites

by Keith CowingApril 16, 2024April 16, 2024

The period of orbital instability that led to the migration of the Solar System’s giant planets to their current orbit occurred between 60 and 100 million years after the beginning […]

We show the transmission spectrum for each reduction in the top panel and the differences between the reductions (in units of sigma) in the bottom panel. All three of our reductions agree per-point, at the ∼2σ level or better, with a median difference of 6ppm. -- astro-ph.EP

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

JWST COMPASS: A NIRSpec/G395H Transmission Spectrum Of The Sub-Neptune TOI-836c

by Keith CowingApril 2, 2024

Planets between the sizes of Earth and Neptune are the most common in the Galaxy, bridging the gap between the terrestrial and giant planets in our Solar System.

This is an artist's concept of a brown dwarf. NASA, ESA, Joseph Olmsted (STScI)

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

Hubble Finds That Brown Dwarf Binary Pairs Are Extremely Rare

by Keith CowingMarch 23, 2024March 23, 2024

It takes two to tango, but in the case of brown dwarfs that were once paired as binary systems, that relationship doesn’t last for very long, according to a recent […]

Left: Average completeness map for the super-Earth RV sample with detected gas giants overplotted in teal. Right: Average completeness map for the super-Earth transit sample with detected gas giants overplotted in teal. Color scale represents detection probability. On average, the RV sample has higher completeness to distant gas giants typically driven by much longer time baselines and more data points. Accounting for differences in individual system sensitivity as well as these broad trends between transit and RV samples is key to calculating frequencies of gas giants in our sample of super-Earth systems. -- astro-ph.EP

Exoplanets, -moons, -comets, Gas Giants, Status Report, Stellar Cartography

Strong Correlation Between Inner Super-Earths And Outer Gas Giant

by Keith CowingMarch 15, 2024

The connection between outer gas giants and inner super-Earths reflects their formation and evolutionary histories. Past work exploring this link has suggested a tentative positive correlation between these two populations, […]