TRAPPIST-1 Archives - Page 9 of 23 - Astrobiology

Joining of the inner and outer subsystems. The evolution of the semi-major axes is shown with continuous coloured lines for all planets, which are also labelled by circles whose size reflect the observed size of the planets. In our favoured scenario, planet e followed the inner edge while planets b, c and d were in the inner cavity. Planets f, g and h join the system later, undergoing inward disc-driven migration (the disc is depicted by the top shaded area, with the lighter shading on the right indicating that the disc will eventually disperse). Since planet g is more massive than f and h, it is likely to capture f in resonance (the 4:3 being the favoured commensurability [5]) and the two planets migrate in together. When f reaches the 3:2 resonance with e, the combined push from g-f is sufficient to dislodge planet e from the inner edge (shown as a blue line enclosing the top shaded area). Driven by a full OLT, the orbit of planet e decays faster than f and g, approaching the 3:2 resonance with d. Planet h is the last one to migrate in and capture g in the 3:2 resonance to complete the chain. -- astro-ph.EP

Exoplanets, -moons, -comets, Status Report, TRAPPIST-1

Forming The Trappist-1 System In Two Steps During The Recession Of The Disc Inner Edge

by Keith CowingAugust 27, 2024August 27, 2024

Trappist-1 hosts 7 planets where period ratios of neighbouring pairs are close to the 8:5, 5:3, 3:2, 3:2, 4:3, and 3:2 ratios in increasing distance from the star. The Laplace […]

Horizontal slices of the O3 number density for our TRAPPIST-1e model at a pressure (altitude) of a) 103 hPa (∼15 km) and b) 609 hPa (∼5 km). The substellar point is at 180° longitude and 0° latitude. N represents the North pole and S represents the South pole. Lower panels show the polar projections. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, TRAPPIST-1

Asymmetries In The Simulated Ozone Distribution On TRAPPIST-1e Due To Orography

by Keith CowingJuly 6, 2024July 6, 2024

TRAPPIST-1e is a tidally locked rocky exoplanet orbiting the habitable zone of an M dwarf star. Upcoming observations are expected to reveal new rocky exoplanets and their atmospheres around M […]

Spectrophotometric transit fits of LHS 1140 b for visit 1 (UT2023-12-01, left) and visit 2 (UT2023-12-26, right) and LHS 1140 c for visit 2 only. The broadband (‘white’) light curves are shown in top panels with the best-fit full model (transit + systematics) shown in black and systematics component only in pink (scaled 10× for clarity). For both visits, examples of 10 systematics-corrected spectroscopic bins are depicted with colored points in bottom panels. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Transmission Spectroscopy of the Habitable Zone Exoplanet LHS 1140 b with JWST/NIRISS

by Keith CowingJune 24, 2024June 24, 2024

LHS 1140 b is the second-closest temperate transiting planet to the Earth with an equilibrium temperature low enough to support surface liquid water.

Cartoon of the planetary envelope in different scenarios, each featuring one volatile species (in blue) and one refractory species (in brown). The infalling pebbles are shown on the left side of the envelope. Initially, they consist of a refractory core (brown dot) and an icy volatile layer (blue ring). On the right side, we show the recycling flows (in magenta) and the dust grains (blue dots) that they carry away. The envelope temperature increases overall from A to D. A: Cold envelope in which the volatile sublimation temperature is not reached. B: The volatile species evaporates in the envelope (indicated by the blue arrows), but the recycling flows do not reach deep enough to prevent the accretion of the volatile. Latent heat is absorbed during the evaporation of the volatile ice (indicated by the red arrows). C: The volatile species evaporates in the envelope and the recycling flows transport the vapor back beyond the volatile evaporation front, where the volatile recondenses onto the dust grains. The dust grains covered in ice are then recycled back into the disk. There is no net latent heat absorption due to the recondensation subsequent to the evaporation. D: Same as C, but the envelope is hot enough to vaporize the refractory species, causing the absorption of latent heat in the process. The refractory vapor is not recycled. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

A Formation Pathway For Terrestrial Planets With Moderate Water Content Involving Atmospheric-volatile Recycling

by Keith CowingJune 14, 2024June 14, 2024

Of the many recently discovered terrestrial exoplanets, some are expected to harbor moderate water mass fractions of a few percent. The formation pathways that can produce planets with these water […]

Comparison of SPECULOOS-3 b with other rocky exoplanets. a) Sizes of host stars and incident stellar flux of known sub-Neptune-sized exoplanets. The size of the symbols scales linearly with the radius of the planet. The background is colour-coded according to stellar size (in units of the Sun’s size), with the ultra-cool dwarf regime shown in orange. The positions of the Solar System terrestrial planets are shown for reference. One can see on this Figure that SPECULOOS-3 b extends the unique planet sample of TRAPPIST-1 to a larger stellar flux. b) SPECULOOS-3 b in the context of other known transiting terrestrial exoplanets (Rp < 1.6R⊕) that are cool enough (Teq < 880 K [80]) to have a dayside made of solid rock (in contrast to hotter magma worlds with molten surfaces). The planets are shown as a function of their radius and their Emission Spectroscopy Metric [62]. They are color-coded as a function of their equilibrium temperature. The shaded green area highlights planetary radii most similar to Earth’s (0.9–1.1 R⊕). The dashed horizontal line represents the threshold of ESM=7.5 recommended by ref. [62] to identify the top targets for emission spectroscopy with JWST. SPECULOOS-3 b is one of the smallest planets amenable to emission spectroscopy with MIRI/LRS. Data from https://exoplanetarchive.ipac.caltech.edu (16th of October 2023). -- astro-ph.EP

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

Detection Of An Earth-sized Exoplanet Orbiting The Nearby Ultracool Dwarf Star SPECULOOS-3

by Keith CowingJune 4, 2024June 4, 2024

Located at the bottom of the main sequence, ultracool dwarf stars are widespread in the solar neighbourhood. Nevertheless, their extremely low luminosity has left their planetary population largely unexplored, and […]

5σ contrast limits at J (bottom left), H (top left), and K (bottom right) from Gemini/NIRI and at K ′ from Keck II/NIRC2 (top right). The combined images are shown in the insets of the panels, where Gliese 12 is at the star symbols. The maximum values of the image dynamic range were set to be 20 times higher than the noise levels at the edge areas. The locations corresponding to the identified possible source that was detected only in the J-band image are marked by arrow symbols and its contrast by a square symbol. Note that the source detection and contrast measurement were performed with the images after PSF subtractions. -- astro-ph.EP

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

Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy

by Keith CowingMay 27, 2024May 27, 2024

Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations.

Gliese 12 b’s estimated size may be as large as Earth or slightly smaller — comparable to Venus in our solar system. This artist’s concept compares Earth with different possible Gliese 12 b interpretations, from one with no atmosphere to one with a thick Venus-like one. CREDIT NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Venus

Gliese 12 b, A Potentially Habitable Exo-Venus With Earth-like Temperature

by Keith CowingMay 23, 2024May 23, 2024

Astronomers have made the rare and tantalising discovery of an Earth-like exoplanet 40 light-years away that may be just a little warmer than our own world.

Joint constraints on the H2/He abundance and the atmospheric pressure on TRAPPIST-1 b resulting from the sequential fit of the stellar contamination and planetary atmosphere. The color shading illustrates the posterior probability density, where darker colors correspond to higher probabilities. Contours indicate the 1σ, 2σ, and 3σ Bayesian credible regions. The displayed posterior probability is marginalized over the H2O, CH4, CO, CO2, NH3, and N2 abundances. Hydrogen-dominated scenarios with high-altitude clouds are at the top left corner of the plot and cloud-free, volatile-rich, high-mean-molecular-mass atmospheres are at the bottom right. Any hydrogen-rich atmospheres without high-altitude clouds, at the bottom left, are robustly ruled out. The second horizontal axis at the top shows the mean molecular mass representative for a pure H2/H2O atmosphere. -- The Astrophysical Journal Letters

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Press Release

JWST’s First Spectrum Of TRAPPIST-1 b

by Keith CowingMay 18, 2024May 18, 2024

In a solar system called TRAPPIST-1, 40 light years from the sun, seven Earth-sized planets revolve around a cold star.

Artist's view of exoplanet SPECULOOS-3 b orbiting its star. The planet is as big as the Earth, while its star is slightly larger than Jupiter, but much more massive. CREDIT NASA/JPL-Caltech

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

Astronomers Discover A New Earth-sized World Orbiting Ultra-cool Star SPECULOOS-3

by Keith CowingMay 16, 2024May 16, 2024

A new, Earth-sized planet orbiting an ultra-cool red dwarf star, has been detected by an international team of astronomers – just 55 light years away.

An artist’s concept of the exoplanet SPECULOOS-3 b orbiting its red dwarf star. The planet is as big around as Earth, while its star is slightly bigger than Jupiter – but much more massive. Credit: NASA/JPL-Caltech

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

Astronomers Discover Earth-sized Exoplanet Orbiting Ultra-cool Star

by Keith CowingMay 15, 2024May 15, 2024

An international scientific team, with the participation of researchers from the Instituto de Astrofísica de Canarias (IAC), confirms the existence of an Earth-sized planet orbiting an ultra-cold red dwarf located […]