transmission spectra Archives

Schematic overview of the interior model of Trappist1f,g,h. The ice I layer is divided into a conductive and a convective sublayer. The thermal model determines the thickness of the conductive and convective layers, Rice,I , RHPI, and Qeq. The tidal model computes the tidal heating rates in the HPI, and the mantle. The layer boundaries are not to scale. Note that the convective layer -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Press Release, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Interior-Atmosphere Coupling on TRAPPIST-1 f, g, and h: Cryovolcanic Water Exospheres and Infrared Detectability

by Keith CowingMay 28, 2026May 28, 2026

We investigate the interior structures and cryovolcanic observability of the exoplanets TRAPPIST-1f, g, and h. Our aim is to determine which interior configurations can sustain subsurface liquid water oceans in […]

Diagram of the dominant chemical reaction pathways in our photochemical network.

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography

A Hycean Interpretation of K2-18b Supported by Photochemical Atmospheric Compositional

by Keith CowingMay 20, 2026May 20, 2026

The nature of the sub-Neptune K2-18b is debated between Hycean and mini-Neptune interpretations.

The figure reports two of the PSFs used to simulate FGS1 (left) and AIRS-CH0 (right). The PSFs are sampled at the sub-pixel level and reported in decibels normalised to the maximum value in the field. The axes report the grid into pixel and micron units. The reader may note that the FGS1 PSF is highly aberrated and complex, so it is sampled on a grid of the same size as the detector (32 × 32), while the AIRS-CH0 PSF is an Airy function and here is reported on a smaller grid. For details, please refer to the software documentation. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Ariel Mission, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography

A Public Dataset Of Ariel Simulated Observations For Developing Exoplanetary Atmosphere Data Reduction Pipelines

by Keith CowingMay 7, 2026May 7, 2026

Detecting and characterising exoplanet atmospheres remains challenging because atmospheric signals can be comparable to residual noise and instrumental/astrophysical systematics. Spectral features span from a few ppm for small planets up […]

Predicted relative transit depth change from the equilibrium chemistry CO2-only model retrieved for CRIRES+ data (green). The model predictions are plotted in high-resolution in the wavelength region overlapping with the CRIRES+ measurements indicated by the grey shaded areas and in low-resolution for the rest of the wavelength range. Space-based measurements from HST (blue) and JWST (orange) are also shown. The 1σ and 1.5σ uncertainties of the model are indicated as darker and lighter green shaded areas, respectively. We also mark the lower 1.1σ uncertainty boundary with a dotted green line as a potential match to the amplitude of the CO2 bump in the JWST measurements at 4200 nm. The HST-WFC3 and JWST NIRSpec G359H measurements were taken from the online data provided by Schlawin et al. (2024) containing the HST data adapted from Kreidberg et al. (2014).-- astro-ph.EP

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

Cloudy With A Chance Of Metals: Indications Of CO2 In The Atmosphere Of GJ 1214 b From High-resolution K-band Spectroscopy

by Keith CowingApril 19, 2026April 19, 2026

Sub-Neptune exoplanets frequently exhibit muted transmission spectra, with GJ 1214 b being the most prominent example. Following years of intense observing campaigns yielding featureless planetary spectra, recent observations with JWST […]

Figure showing the contribution of different gases to the best-fit spectrum obtained from the free chemistry retrieval binned down to R∼200, for STIS+WFC3+NIRCam observations. -- astro-ph.EP

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

A Detailed Investigation of HD 209458 b HST & JWST Transmission Spectra with SANSAR

by Keith CowingMay 14, 2025May 14, 2025

HD 209458 b is the first exoplanet on which an atmosphere was detected. Since then, its atmosphere has been investigated using multiple telescopes and instruments. However, many of its atmospheric […]

Absorption contributions from different molecules in a potentially inhabited TRAPPIST-1 e spectrum with surface concentrations similar to a Neoproterozoic Earth (Kaltenegger et al. 2020) and a mixing ratio of H2O fixed at 10−2 . Each color represents a molecule (see legend). Error bars illustrate noise based on the SNR, using the CO2 strongest peak as the signal value. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Machine-assisted Classification Of Potential Biosignatures In Earth-like Exoplanets Using Low Signal-to-noise Ratio Transmission Spectra

by Keith CowingApril 5, 2025April 5, 2025

The search for atmospheric biosignatures in Earth-like exoplanets is one of the most pressing challenges in observational astrobiology. Detecting biogenic gases in terrestrial planets requires high resolution and long integration […]

Various reduction steps applied for an individual ESPRESSO order of DS1. (a) Before telluric removal with molecfit. (b) After telluric removal with molecfit and shifted to the stellar rest frame. (c) Each spectrum is placed on a common blaze function (see Sect. 2.4). (d) Residuals after division through by the mean out-of-transit spectrum, weighted on their uncertainties. This panel shows the final data product used in the molecfit preprocessing analysis. (e) Residuals after division through by the mean out-of-transit spectrum, weighted on their uncertainties, and subtraction of the SysRem model. This panel shows the final data product used in the SysRem preprocessing analysis. It is worth noting that for this procedure, we do not perform any preceding telluric removal (i.e., Sect. 2.4, Step (2)). (f) A magnification of panel (e) showing the wavelength shifts caused by each injected model. The planetary velocity curve for P2 is shown as a white dashed curve, whereas the slower moving planet’s (P12) velocity curve is shown as a white dotted curve. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Assessing Methods for Telluric Removal On Atmospheric Retrievals of High-resolution Optical Exoplanetary Transmission Spectra

by Keith CowingOctober 29, 2024October 29, 2024

Recent advancements in ultra-stable ground-based high-resolution spectrographs have propelled ground-based astronomy to the forefront of exoplanet detection and characterisation. Retrieving accurate atmospheric parameters depends on accurate modelling and removal of […]

CRIRES+ data: CCFo map for night 3, channel B, using the H2O template. The horizontal white lines represent the orbital phases of the HD 209458 b’s expected transit ingress (bottom) and egress (top). The slanted line represent HD 209458 b’s expected radial velocities, corrected from the barycentric velocities, with Vrest = 0 km·s −1 . Rest velocities lower than −25 km·s −1 and larger than +35 km·s −1 are not shown for clarity. -- astro-ph.EP

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

Four HD 209458 b Transits Through CRIRES+: Detection of H2O and Non-detections of C2H2, CH4, and HCN

by Keith CowingAugust 28, 2024August 27, 2024

HD 209458 b is one of the most studied exoplanets to date. Despite this, atmospheric characterisation studies yielded inconsistent species detections and abundances. Values reported for the C/O ratio range […]

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

Effect Of Multiple Scattering On The Transmission Spectra And The Polarization Phase Curves For Earth-like Exoplanets

by Keith CowingJanuary 23, 2023January 23, 2023

It is the most appropriate time to characterize the Earth-like exoplanets in order to detect biosignature beyond the Earth because such exoplanets will be the prime targets of big-budget missions […]

transmission spectra

Interior-Atmosphere Coupling on TRAPPIST-1 f, g, and h: Cryovolcanic Water Exospheres and Infrared Detectability

A Hycean Interpretation of K2-18b Supported by Photochemical Atmospheric Compositional

A Public Dataset Of Ariel Simulated Observations For Developing Exoplanetary Atmosphere Data Reduction Pipelines

Cloudy With A Chance Of Metals: Indications Of CO2 In The Atmosphere Of GJ 1214 b From High-resolution K-band Spectroscopy

A Detailed Investigation of HD 209458 b HST & JWST Transmission Spectra with SANSAR

Machine-assisted Classification Of Potential Biosignatures In Earth-like Exoplanets Using Low Signal-to-noise Ratio Transmission Spectra

Assessing Methods for Telluric Removal On Atmospheric Retrievals of High-resolution Optical Exoplanetary Transmission Spectra

Four HD 209458 b Transits Through CRIRES+: Detection of H2O and Non-detections of C2H2, CH4, and HCN

Effect Of Multiple Scattering On The Transmission Spectra And The Polarization Phase Curves For Earth-like Exoplanets

Dragonfly Titan Astrobiology Droid Clears Key Tests

Expedition Led By MBARI Researchers Reveals A Remarkable, And Rare, Form Of Deep-sea Hydrothermal Vents

SwRI Study Found Primordial Mini-moons May Explain Meteorite Composition

The Galactic Centre G+0.633-0.0604 Molecular Cloud: A New Astrochemical Gold Mine. I. Gas Physical Properties

Researchers Confirm The Cause Of Earth’s Biggest Mass Extinction