warm-Neptune Archives

Left: T1 (top) and T2 (bottom) tomography maps in the stellar rest frame around the Hα line.

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

The Atmosphere Of The Warm Neptune GJ 436 b Probed With ESPRESSO

by Keith CowingMay 5, 2026May 5, 2026

Aims. We aim to identify the presence of atomic and molecular species in the upper atmosphere of the warm Neptune-sized transiting planet GJ 436 b, which has a radiative equilibrium […]

Example full-resolution Ariel transmission spectrum of the hot-Saturn WASP-39 b simulated at Tier 2 precision (black error bars). The underlying atmosphere model assumes chemical equilibrium with a solar C/O ratio (0.54), 10× solar metallicity, and no clouds. The opacity contributions of individual species to the total spectrum are shown with different colours and represent the major chemical species with significant opacity in the Ariel wavelength range. The wavebands of Ariel’s instruments are labelled underneath the spectrum. -- astro-ph.EP

Ariel Mission, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Status Report

On The Information Content of Ariel Transmission Spectra: Reassessing The Tier System

by Keith CowingApril 10, 2026April 10, 2026

The European Space Agency’s Ariel mission will conduct a survey of the atmospheric properties of exoplanets around bright stars.

Secular evolution of the obliquities of TOI-1710 from four-body secular integrations. The semimajor axis of the intermediate companion varies across panels. The obliquity evolution of TOI-1710 A b (red) and the hypothetical intermediate companion X (blue) are shown. The companion mass is fixed at 9 MJ and the initial mutual inclination with the M-dwarf is iXB = 55◦ . The green region marks the 2σ constraints on the obliquity of the observed planet, with the fraction of time spent within this region indicated by fobs. Panels (a) and (c) remain within the allowed window for much less time than panel (b). In all cases, the eccentricity of planet b remains nearly the same as the initial value. -- astro-ph.EP

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

POSEIDON II: The Anti-Aligned Orbit of the Warm Neptune TOI-1710 A b

by Keith CowingApril 7, 2026April 7, 2026

We present an observation of the Rossiter-McLaughlin effect for the warm-Neptune system TOI-1710 obtained with the NEID spectrograph on the WIYN 3.5 m telescope.

Stability analysis of the TOI-6041 system. The phase space of the system is explored by varying the orbital period Pi and eccentricity ei of each planet independently. For each initial condition (Table 4), the system is integrated over 10 kyr, and a stability criterion is derived with the frequency analysis of the mean longitude. The chaotic diffusion is measured by the variation in the frequencies. The color scale corresponds to the logarithmic variation in the stability index used in (Correia et al. 2010). The red zone corresponds to highly unstable orbits, while the dark blue region can be assumed to be stable on a billion-year timescale. White dashed lines indicate the nominal orbital periods reported in Table 4. -- astro-ph.EP

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

Giant Outer Transiting Exoplanet Mass (GOTEM) Survey.VII. TOI-6041: A Multi-planet System Including A Warm Neptune Exhibiting Strong TTVs

by Keith CowingDecember 28, 2025December 28, 2025

We present the characterization of the TOI-6041 system, a bright (V=9.84±0.03) G7-type star hosting at least two planets.

Baade/MagE spectrum of TOI-2407 compared to the M2 SDSS template from Bochanski et al. (2007, magenta line). Data are normalized at 7400 Å, and key spectral features across the 4300–8100 Å region are labelled, including the location of uncorrected telluric oxygen and water bands (⊕). The inset box show the 6555–6585 Å region with H𝛼 and Ca I absorption features labelled. -- astro-ph.EP

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

TOI-2407 b: A Warm Neptune In The Desert

by Keith CowingJune 10, 2025June 10, 2025

We present the validation of TOI-2407 b, a warm Neptune-sized planet with a radius of 4.26 ± 0.26 R⊕, orbiting an early M-type star with a period of 2.7 days […]

UV absorption cross sections for the phosphorus species in the network that undergo photolysis reactions. The photolysis threshold wavelength for each species is indicated by the coloured arrows. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Jupiter, Saturn, Status Report, Water/Hycean Worlds & Oceanography

A Photochemical PHO Network For Hydrogen-dominated Exoplanet Atmospheres

by Keith CowingSeptember 13, 2024September 13, 2024

Due to the detection of phosphine PH3 in the Solar System gas giants Jupiter and Saturn, PH3 has long been suggested to be detectable in exosolar substellar atmospheres too. However, […]

Interpretation of WASP-107b’s transmission spectrum. The observed transmission spectrum of the planet with 1σ error bars is compared to the best-fit one-dimensional radiative-convective-photochemical equilibrium models (1D-RCPE model, χ 2/Ndata=1.4) shown at a spectral resolution of R=300. The colored shaded regions show the contributions from individual gases to the best fit model. The gray dashed line shows the clear atmosphere component of the model, that is, the gas contributions without the presence of clouds or hazes. Panel a shows the broad wavelength spectrum (0.8–12 µm) of the planet. Panel b shows the fit residuals with the corresponding 2σ data error envelope. Panel c shows the NIRCam observations, while d shows HST WFC3 spectra and e shows JWST MIRI observations. The HST/WFC3 data are binned at a constant ∆λ = 0.025 µm, the NIRCam data are binned at ∆λ = 0.015 µm, and the MIRI data are binned at ∆λ = 0.15025 µm. astro-ph.EP

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

A High Internal Heat Flux and Large Core in a Warm Neptune Exoplanet

by Keith CowingMay 22, 2024May 22, 2024

Interactions between exoplanetary atmospheres and internal properties have long been hypothesized to be drivers of the inflation mechanisms of gaseous planets and apparent atmospheric chemical disequilibrium conditions.

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

Webb Studies Inflated Exoplanet WASP-107 b

by Keith CowingMay 20, 2024May 20, 2024

Why is the warm gas-giant exoplanet WASP-107 b so puffy? Two independent teams of researchers have an answer.

SVD/PCA based detrending process and the effect of model reprocessing for order number 11 of Night 1 of CARMENES observation. (a) Data after calibration through CARACAL, (b) After SVD/PCA based detrending and strong residual masking - the orange line shows the cross-section along which the spectra for (e) is drawn, (c) Nominal exoplanet model signal that is to be injected into noiseless data matrix before reprocessing - the black line represents the cross-section for drawing the spectrum in (f), (d) Reprocessed model signal showing the model signal + artefacts in the out-of-transit phases - blue is the cross-section for drawing (g) and reddish brown for (h), (e) Cross-section at mid-transit time (Phase = 0) for the processed and normalised data in (b) showing variations around 1.0, (f) Same as (e) but for the nominal model signal in (c), (g) Same as (e) but for the reprocessed model signal in (d). The differences between (f) and (g) notably in the line depths and wing shapes illustrate the effect of the SVD/PCA based detrending procedure on the the model signal and by definition any actual signal that would be present in the data, (h) Cross-section at an out-of-transit time (Phase ≈ 0.02) showcasing the nature of the artefacts caused due to model reprocessing with a similar scale as in (g). -- astro-ph.EP

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

Constraints On Atmospheric Water Abundance and Cloud Deck Pressure in the Warm Neptune GJ 3470 b via CARMENES Transmission Spectroscopy

by Keith CowingApril 11, 2024April 11, 2024

Observations of cooler atmospheres of super-Earths and Neptune sized objects often show flat transmission spectra.

Three dimensional view of the magnetised stellar wind for Models I and II. The surface magnetic field from March-June 2016 reconstructed by Bellotti et al. (2023) is used at the boundary of the models. The grey streamlines are the magnetic field lines embedded in the wind. The rotation axis of the star is along the z⋆-axis. The two-dimensional cut is placed at the x⋆z⋆ plane, and for indication, the orbital distance of the planet is shown by the translucent sphere at 14.56 R⋆ ≃ 0.028 au. The contour shows the wind velocity and the Alfvén surface is shown by the translucent outer surface. Models I and II predict stellar wind mass-loss rates of 1.1 × 10−15 M⊙ yr−1 and 2.5 × 10−14 M⊙ yr−1 -- astro-ph.SR .

Exoplanets, -moons, -comets, Extinction events, Habitable Zones, Space Weather & Heliophysics, Status Report

The Space Weather Around The Exoplanet GJ 436 b. II. Stellar Wind-exoplanet Interactions

by Keith CowingSeptember 5, 2023September 5, 2023

The M dwarf star GJ 436 hosts a warm-Neptune that is losing substantial amount of atmosphere, which is then shaped by the interactions with the wind of the host star. […]

warm-Neptune

The Atmosphere Of The Warm Neptune GJ 436 b Probed With ESPRESSO

On The Information Content of Ariel Transmission Spectra: Reassessing The Tier System

POSEIDON II: The Anti-Aligned Orbit of the Warm Neptune TOI-1710 A b

Giant Outer Transiting Exoplanet Mass (GOTEM) Survey.VII. TOI-6041: A Multi-planet System Including A Warm Neptune Exhibiting Strong TTVs

TOI-2407 b: A Warm Neptune In The Desert

A Photochemical PHO Network For Hydrogen-dominated Exoplanet Atmospheres

A High Internal Heat Flux and Large Core in a Warm Neptune Exoplanet

Webb Studies Inflated Exoplanet WASP-107 b

Constraints On Atmospheric Water Abundance and Cloud Deck Pressure in the Warm Neptune GJ 3470 b via CARMENES Transmission Spectroscopy

The Space Weather Around The Exoplanet GJ 436 b. II. Stellar Wind-exoplanet Interactions

PJ Harvey Announces New Song “Voyager”

Fifty Years after Viking: The Promise of Solar System Microbiology and Microbial Ecology

Characterising Transiting Exoplanets At Long Orbital Period: Lessons Learned For PLATO From 10 Years Of Monitoring The HIP41378 System

Implications Of Self-consistent H2O Ice Optical Constants On Radiative Transfer Models Of Disks

The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c