super Earth Archives

Snapshot of the triple transit of planet b, c, and d as seen by K2 at the end of 2016. This artistic representation has been created with the software tango (https://github.com/oscaribv/tango).

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

Discovery Of A Multi-planetary System Orbiting The Aged Sun-like Star HD 224018

by Keith CowingAugust 23, 2025August 23, 2025

In 2016, Kepler/K2 detected a system of two sub-Neptunes transiting the star HD 224018, one of them showing a mono-transit event.

Maximum predicted emission frequency and radio flux density for known exoplanets (triangle symbols; data from [8]). The uncertainties on the predictions are estimated to one order of magnitude for the flux density and a factor of 2-3 for the emission frequency12. The sensitivities for the ground-based (UTR-2, LOFAR, NenuFAR, SKA-Low, VLA, GMRT) and space-based (FARSIDE, LCRT, FARVIEW ) radio telescopes are labeled (for 10 min of integration time and a bandwidth of 24 MHz). The FARVIEW and LCRT sensitivity curves are taken from [19] and [2], respectively. The LuSEE-Night sensitivity curve is averaged over the entire two-year mission and includes post-processing using a LombScargle periodogram (see text for details). The possible detection of τ Boo b from LOFAR23 is shown as a red star. This figure is adapted from [9]. -- astro-ph.IM

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Magnetic Fields, Electromagnetism, bioelectricity,, Status Report

Studying Exoplanets In The Radio From The Moon

by Keith CowingAugust 14, 2025August 14, 2025

Exoplanets with and without a magnetic field are predicted to form, behave, and evolve very differently.

Modeled transit spectra of GJ 1214b including haze and graphite scenarios.

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

The Impact Of Organic Hazes And Graphite On The Observation Of CO2-rich Sub-Neptune Atmospheres

by Keith CowingAugust 14, 2025August 14, 2025

Many sub-Neptune and super-Earth exoplanets are expected to develop metal-enriched atmospheres due to atmospheric loss processes such as photoevaporation or core-powered mass loss.

The upper panel illustrates the mass loss processes and potential formation of graphite in sub-Neptune atmospheres within the graphitestability regime. The lower panel presents the atmospheric compositions calculated from the thermochemical equilibrium model without and with graphite. -- astro-ph.EP

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

Formation Of Organic Hazes In CO2-rich Sub-Neptune Atmospheres Within The Graphite-stability Regime

by Keith CowingAugust 13, 2025August 13, 2025

Super-Earths and sub-Neptunes are the most common exoplanets, with a “radius valley” suggesting that super-Earths may form by shedding sub-Neptunes’ gaseous envelopes.

Eccentricity of inner super-Earth vs. the semimajor axis ratio between the outer cold Jupiter and the inner super-Earth from observations, with the color of the symbol showing the semimajor axis of the inner super-Earth. The red boxes mark the systems with multiple inner super-Earths. -- astro-ph.EP

Exoplanets, -moons, -comets, Status Report

Dynamical Instability of Multi-planet Systems and Free-floating Planets

by Keith CowingJuly 31, 2025July 31, 2025

The ejection of planets by the instability of planetary systems is a potential source of free-floating planets.

Logarithm of exomoon lifetime (log10 (𝑡max ); color coded) from stability simulations that vary a host planet’s mass, tidal constant time-lag, 𝜏p, and initial eccentricity while using Earth-like parameters for the 𝑘2 Love number and moment of inertia constant, 𝐶. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Can Moons Exist Around The Habitable-zone Planet K2-18 b?

by Keith CowingJuly 18, 2025July 18, 2025

K2-18 b closely orbits a nearby M3 dwarf within its habitable zone, where this planet could be either a super-Earth or a mini-Neptune.

Family portrait of the five planets in the L 98-59 system showing their transit (or absence of transit) observed by TESS in the top panels and their Doppler signature from HARPS (red circles) and ESPRESSO (white/black circles for pre/post data) in the bottom panels. Only the error bars for ESPRESSO are shown to improve visibility. Black curves represent best-fit models from the transit analysis (top) and joint RV–TTV fit (bottom, using fixed orbital inclinations, see Sect. 4.5). For L 98- 59 e and f, 1000 predicted transit curves are shown in red using posterior samples from the RV–TTV fit and radii estimated from their minimum masses using spright (Parviainen et al. 2024). Planets e and f do not transit L 98-59. -- astro-ph.EP

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

Detailed Architecture Of The L 98-59 System And Confirmation Of A Fifth Planet In The Habitable Zone

by Keith CowingJuly 16, 2025July 16, 2025

The L 98-59 system, identified by TESS in 2019, features three transiting exoplanets in compact orbits of 2.253, 3.691, and 7.451 days around an M3V star, with an outer 12.83-day […]

The atmospheric compositions ruled out by the Tiberius dataset binned at 60 pixels.

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

JWST COMPASS: A NIRSpec G395H Transmission Spectrum Of The Super-Earth GJ 357 b

by Keith CowingJuly 12, 2025July 12, 2025

We present JWST NIRSpec/G395H transmission spectroscopy observations of GJ 357 b, a warm (Teq≈525 K) super-Earth (1.2 R⊕, 1.84 M⊕) orbiting a nearby M3-type star, with a median precision of […]

Distribution of 339 planets in the stellar effective flux (𝑆eff) versus stellar temperature (𝑇eff) space. Red solid circles indicate the 17 planets orbiting within the EHZ, while gray points depict the remaining planets. Solar system planets are marked with purple circles. The green solid lines correspond to the inner and outer edges of the classical 1D habitable zone, as defined by Kopparapu et al. (2013). The blue dashed line represents the inner edge of the Extended Habitable Zone (EHZ) around M dwarf stars, assuming 30% heat transport efficiency (Wandel 2023a). The brown curve marks the outer edge of the EHZ, determined by the melting of ice sheets driven by geothermal heat (Wandel 2023b). The gray dashed line indicates the tidally locked radius around M dwarf stars. The green shaded region defines the classical HZ and the blue shaded region highlights the extended HZ for tidally locked exoplanets. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Exploring The Habitability And Interior Composition Of Exoplanets Lying Within The Extended Habitable Zone

by Keith CowingJuly 8, 2025July 8, 2025

Studying the habitability, internal structure and composition of exoplanets is crucial for understanding their potential to sustain life beyond our solar system.

Planetary growth timescales in an irradiated disc

Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Icy Worlds, Status Report

Super-Earth Formation In Systems With Cold Giants

by Keith CowingJune 29, 2025June 28, 2025

Around our Sun, terrestrial planets did not grow beyond Earth in mass, while super-Earths are found to orbit approximately every other solar-like star.