super Earth Archives

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, […]

Broadband and spectroscopic light-curve fits of the NIRISS/SOSS (left) and NIRSpec/G395H (right) transits of TOI-270 d. For both instruments, examples of 10 normalized and systematics-corrected light curves are shown (colored points) along with their best-fitting transit models (black lines) and labelled with the central wavelength of the spectroscopic channel. Broadband light-curve fits (white) are also shown at the top for Order 1 in the NIRISS/SOSS case, and for NRS1 in the NIRSpec/G395H case. For clarity, the spectroscopic light curves are plotted with a relative flux offset. For NIRSpec/G395H, light curves with wavelengths below 3.8 µm are from the NRS1 detector and the remaining from NRS2. For visual purposes, the light curves are also binned in time in groups of 10 (NIRISS/SOSS) and 20 (NIRSpec/G395H) data points, resulting in 3.6 minute bins. A full transit of planet b occurs at the start of the NIRSpec/G395H exposure, with both transits overlapping shortly as planet d starts transiting. All light curves are well-behaved, with no signs of spot-crossing events or Hα flares. -- astro-ph.EP

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

JWST Reveals CH4, CO2, and H2O in a Metal-rich Miscible Atmosphere on a Two-Earth-Radius Exoplanet

by Keith CowingMarch 7, 2024March 7, 2024

Even though sub-Neptunes likely represent the most common outcome of planet formation, their natures remain poorly understood.

Transmission spectrum of TOI-270 d observed with JWST/NIRSpec G395H and HST/WFC3. The NIRSpec G395H spectrum between 2.7 - 5.2 µm, from this work, is shown in dark red, binned to R ≈ 55 for visual clarity. The WFC3 spectrum is shown in orange and spans 1.1 - 1.6 µm, reported by Mikal-Evans et al. (2023). The retrieval is performed using the native resolution NIRSpec G395H spectrum (R ∼ 2700) and the WFC3 spectrum. The NIRSpec spectrum is vertically offset by −84 ppm, corresponding to the median retrieved offset in the canonical one-offset case. The blue curve shows the median retrieved model spectrum, while the medium- and lighter-blue contours denote the 1σ and 2σ intervals, respectively. Yellow points correspond to the median spectrum binned to match the observations. The prominent molecules responsible for the features in different spectral regions are labelled. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Possible Hycean Conditions In The sub-Neptune TOI-270 d

by Keith CowingMarch 7, 2024March 7, 2024

The JWST has ushered in a new era in atmospheric characterisations of temperate low-mass exoplanets with recent detections of carbon-bearing molecules in the candidate Hycean world K2-18 b.

Our super-Earth models are shown in dark-blue circles, compared with a sample of observed exoplanets from the NASA Exoplanet archive with masses and radii constrained to 20% and 5% respectively. In the left-hand panel, we show the mass-radius diagram, whereas, in the right-hand panel, we show normalised density as a function of planet mass, which is the density of each planet when scaled to be 1M⊕. Grey lines represent an Earth-like density of ∼ 5.5 g cm−1 . The blue-shaded region is the inferred 1σ range in interior density from the population-level evolution analysis from Rogers & Owen (2021). The orange-shaded region is the range of plausible sizes (or densities) of sub-Neptunes hosting significant hydrogen-dominated atmospheres from Rogers et al. (2023c), which accounts for thermal evolution, including cooling and mass loss. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report

The Imprint of Escaping Hydrogen Atmospheres on Super-Earth Interiors

by Keith CowingFebruary 23, 2024February 23, 2024

Small, close-in exoplanets are divided into two sub-populations: super-Earths and sub-Neptunes. Most super-Earths are thought to have lost their primordially accreted hydrogen-dominated atmospheres via thermally driven winds.

Contrast curves around TOI-1347 from Gemini/‘Alopeke; the inset shows the reconstructed image at 832 nm. No companions are detected. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Imaging & Spectroscopy, Status Report

The TESS-Keck Survey. XII. A Dense 1.8 R⊕ Ultra-Short-Period Planet Possibly Clinging to a High-Mean-Molecular-Weight Atmosphere After the First Gyr

by Keith CowingFebruary 13, 2024February 13, 2024

The extreme environments of ultra-short-period planets (USPs) make excellent laboratories to study how exoplanets obtain, lose, retain, and/or regain gaseous atmospheres.

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 […]

Mass-radius diagram of transiting exoplanets with well established mass and radius from the NASA Exoplanet archive along with some theoretical composition curves (Zeng et al. 2019). The purple squares highlight the transiting planets orbiting K-dwarfs. The green blobs show the mass and radius posteriors (1- and 2-σ contours) of TOI–238 b and c. The planets of the solar system are included as reference. -- astro-ph.EP

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

TESS and ESPRESSO Discover A Super-Earth And A Mini-Neptune Orbiting The K-dwarf TOI-238

by Keith CowingFebruary 7, 2024February 7, 2024

The number of super-Earth and mini-Neptune planet discoveries has increased significantly in the last two decades thanks to transit and radial velocity surveys. When it is possible to apply both […]

This illustration shows one way that planet TOI-715 b, a super-Earth in the habitable zone around its star, might appear to a nearby observer. NASA/JPL-Caltech

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

Super-Earth Discovered In The Habitable Zone Of TOI-715

by Keith CowingFebruary 1, 2024February 1, 2024

The discovery: A “super-Earth” ripe for further investigation orbits a small, reddish star that is, by astronomical standards, fairly close to us – only 137 light-years away. The same system […]

Partial pressures of most abundant species in the vapor calculated using the Equilibrium method (left plot, same as Fig B.3 from Charnoz et al. (2023)) and the Sum method (right plot, methodology of Zilinskas et al. (2023); Piette et al. (2023)), for different monoatomic hydrogen pressure P0 H when the atmosphere is at equilibrium with the magma ocean at T = 3000 K and hydrogen is not in equilibrium with the magma ocean. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Lava / magma ocean / Volcanic Worlds, Status Report

Hydrogenated Atmospheres Of Lava Planets: Atmospheric Structure And Emission Spectra

by Keith CowingJanuary 29, 2024May 11, 2024

Hot rocky super-Earths are thought to be sufficiently irradiated by their host star to melt their surface and thus allow for long-lasting magma oceans.

TOI-2266 b’s location in the period-radius plane with the currently known planets orbiting M dwarfs. The planets without sufficiently precise density estimates are shown as grey crosses (From exoplanet.eu, accessed 2023 April 24), while the planets with well-constrained densities from the catalogue by Luque & Pallé (2022) are separated by their likely type: rocky planets are shown as black dots, water worlds as blue circles, and sub-Neptunes as green circles. The upper radius limits for rocky planets for the gas-depleted formation and thermally-driven mass loss scenarios are drawn as dashed lines. -- astro-ph.EP

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

TOI-2266 b: A Keystone Super-Earth At The Edge Of The M dwarf Radius Valley

by Keith CowingJanuary 24, 2024January 23, 2024

We validate the Transiting Exoplanet Survey Satellite (TESS) object of interest TOI-2266.01 (TIC 348911) as a small transiting planet (most likely a super-Earth) orbiting a faint M5 dwarf (V=16.54) on […]

super Earth

Strong Correlation Between Inner Super-Earths And Outer Gas Giant

JWST Reveals CH4, CO2, and H2O in a Metal-rich Miscible Atmosphere on a Two-Earth-Radius Exoplanet

Possible Hycean Conditions In The sub-Neptune TOI-270 d

The Imprint of Escaping Hydrogen Atmospheres on Super-Earth Interiors

The TESS-Keck Survey. XII. A Dense 1.8 R⊕ Ultra-Short-Period Planet Possibly Clinging to a High-Mean-Molecular-Weight Atmosphere After the First Gyr

Migration Solves An Exoplanet Puzzle

TESS and ESPRESSO Discover A Super-Earth And A Mini-Neptune Orbiting The K-dwarf TOI-238

Super-Earth Discovered In The Habitable Zone Of TOI-715

Hydrogenated Atmospheres Of Lava Planets: Atmospheric Structure And Emission Spectra

TOI-2266 b: A Keystone Super-Earth At The Edge Of The M dwarf Radius Valley

ExoPAG 35 – Early Career Talks Invitation

Missed Detections and False Alarms in a CNN Technosignature Detector on Breakthrough Listen Data

Ancient Clays Near The Hellas Basin On Mars

A Hydrogen Atmosphere Could Keep Exomoons Habitable For Billions Of Years

Ring Pattern Reveal The Mechanism By Which Unseen Planets And Dust Particles Gather On Their Own