Transmission spectroscopy Archives

Patterns of atmospheric asymmetry and their different impacts on light curves. The blue solid lines and grey dashed lines in the figures on the right of each panel correspond to the light curves of the blue and grey disks of the planet’s shadow in the schematics on the left, respectively. (a) A displacement of the planet’s shadow along the X–axis (morning-evening asymmetry) causes a shift of the central transit time t0. (b) A displacement along the Y –axis (north-south asymmetry) causes a change in the transit duration. (c) Opposite displacements along the X–axis between ingress and egress also alter the transit duration. (d) Changes in the apparent radius result in variations in both the transit depth and duration. In Panel (d), the radius of the blue disk is exaggerated by a factor of 5 compared to the disk producing the blue light curve, to highlight the differences between the grey and blue disks. -- astro-ph.EP

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

Probing 2D Asymmetries Of An Exoplanet Atmosphere From Chromatic Transit Variation

by Keith CowingMarch 17, 2025September 18, 2025

We propose a new method for investigating atmospheric inhomogeneities in exoplanets through transmission spectroscopy. Our approach links chromatic variations in conventional transit model parameters (central transit time, total and full […]

Planet mass versus equilibrium temperature with each point color-coded representing their CO2-L index value. The background color gradients are model predictions from the PLATON generic grid under Solar System mass-metallicity trend or uniform metallicity assumptions. -- astro-ph.EP

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

Statistical Trends In JWST Transiting Exoplanet Atmospheres

by Keith CowingJanuary 10, 2025January 10, 2025

Our brains are hardwired for pattern recognition as correlations are useful for predicting and understanding nature. As more exoplanet atmospheres are being characterized with JWST, we are starting to unveil […]

The spectral decomposition of the Reference case retrieval of WASP-166b with the absorption contributions of the key atmospheric constituents shown. Spectra are plotted with resolution R = 100 for clarity. The combined forward model, shown as a heavy black line, is the median Reference retrieval result (see Table 5). The colored lines correspond to the individual opacity/absorption contributions (including Rayleigh scattering and collision absorption) of the various constituent molecules and clouds at specific wavelengths. (H2S is plotted but is not distinguishable from the bulk species line.) The transmission spectrum is dominated by contributions from H2O (15.2σ), and CO2 (14.7σ). The more subtle effects of NH3 (2.3σ) may be apparent at ∼ 2.3 µm, and possibly at ∼ 3.9 µm. The effects of the cloud deck (flat purple line at transit depth of ∼ 0.274 x10−2 ) are apparent in clipping the troughs of the water features from 0.85 to 1.7 µm -- astro-ph.EP

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

Detection of H2O and CO2 in the Atmosphere of the Hot Super-Neptune WASP-166b with JWST

by Keith CowingJanuary 3, 2025January 3, 2025

We characterize the atmosphere of the hot super-Neptune WASP-166b (P=5.44 d, Rp=6.9±0.3 R⊕, Mp=32.1±1.6 M⊕, Teq=1270±30 K) orbiting an F9V star using JWST transmission spectroscopy observations obtained with NIRISS SOSS […]

Artist's illustration of the exoplanet WASP-107b based on transit observations from NASA's James Webb Space Telescope as well as other space- and ground-based telescopes. Credit: Rachel Amaro/University of Arizona

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

Astronomers Catch A Glimpse Of A Uniquely Inflated And Asymmetric Exoplanet

by Keith CowingSeptember 25, 2024September 25, 2024

Astronomers from the University of Arizona, along with an international group of researchers, observed the atmosphere of a hot and uniquely inflated exoplanet using NASA’s James Webb Space Telescope. The […]

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.

A5 Apparent chromatic offsets in WASP-107b’s time of conjunction with wavelength due to limb asymmetry. Shown are the best-fit times of conjunction as a function of wavelength when fitting our JWST/NIRCam F322W2 data by itself. We fit the data using a uniformlimb transit model, described in Section 3.4.2, fitting only for tc, the planet-star radius ratio, and a linear flux vs. time ramp model. The black points are the result from fitting each of our thirty spectroscopic light curves. The purple line is the result from fitting the broadband light curve, with the shaded region representing the 1-σ uncertainty. We show the difference between these results and the joint-fit time of conjunction derived by fitting other multi-wavelength data sets simultaneously, whose uncertainty is shown as the green shaded region. The observed difference is due to the significant evening-morning limb asymmetry on WASP-107b at these wavelengths. -- astro-ph.EP

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

Evidence for Morning-to-Evening Limb Asymmetry on the Cool Low-Density Exoplanet WASP-107b

by Keith CowingJune 22, 2024June 22, 2024

Transmission spectroscopy has enabled unprecedented insights into the makeup of exoplanet atmospheres. A transmission spectrum combines contributions from a planet’s morning and evening limbs, but these limbs may have different […]

Phase curves for the 9 planet candidates, showing TESS data in black. Orange lines show fitted transit models, while orange circles represent the underlying data averaged every 15 minutes. -- astro-ph.EP

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

9 New M Dwarf Planet Candidates From TESS Including 5 Gas Giants

by Keith CowingJune 13, 2024June 13, 2024

We present the detection of 9 new planet candidates orbiting M dwarfs, identified using an independent search and vetting pipeline applied to TESS Full-Frame Image (FFI) data from Sectors 1 […]

2D color map showing the transmission spectra - 1 divided by the out-of-transit column standard deviation at each pixel at different orbital phases for the Na d2 line (top) and Na d1 line (bottom) in the stellar restframe. Cyan dashed lines mark the 1st - 4th contact and the purple dashed lines mark the 2nd - 3rd contact. The black dashed lines illustrate the planetary absorption trajectory. Left: Transmission spectra before correcting with RM-CLV-model. Right: Transmission spectra corrected with the RM-CLV-model. -- astro-ph.EP

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

The PEPSI Exoplanet Transit Survey (PETS). V: New Na D Transmission Spectra Indicate A Quieter Atmosphere On HD 189733b

by Keith CowingApril 23, 2024April 23, 2024

Absorption lines from exoplanet atmospheres observed in transmission allow us to study atmospheric characteristics such as winds.

Different scenarios of super-rotating atmospheric material. Panels a, b and c show the scenario of a homogeneously rotating planet. The purple solid line shows the velocity kernel of the material at rotation consistent with tidally locked rotation (panel b) and the resulting shape of the cross-correlation function (panel c). The turquoise dashed line shows the effect of the planet rotating approximately six times faster. Panels d, e and f show two cases of a super-rotating equatorial jet, with the poles rotating at tidally locked velocities. The difference between the two cases is the opening angle of the equatorial region (35◦ orange dashed, and 65◦ solid green). Panels g, h and i explore the case of the velocity kernel of a super-rotating equatorial jet (blue and red solid lines in panel h) with the polar region represented by the velocity kernel of super-rotating velocity (grey dash-dotted line) or tidally locked velocity (grey dotted line) but not contributing to the transmission spectrum due to muted atmospheric features, leading in both cases to only two peaks in the CCF (panel i). -- astro-ph.EP

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

CRIRES+ Transmission Spectroscopy of WASP-127b. Detection Of The Resolved Signatures Of A Supersonic Equatorial Jet And Cool Poles In A Hot Planet

by Keith CowingApril 20, 2024April 20, 2024

General circulation models of gas giant exoplanets predict equatorial jets that drive inhomogeneities across the planetary atmosphere. We studied the transmission spectrum of the hot Jupiter WASP-127b during one transit […]

True 3D obliquity of known exoplanets as a function of the effective temperature of the host star, Teff. Each exoplanet except for TOI5398 (star marker) is represented by a circle. The stellar age is colour coded. The data were taken from TEPCat, NASA Exoplanet Archive, and GAPS (priv. comm.) in January 2024. -- astro-ph.EP

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

Orbital Obliquity of the Young Planet TOI-5398 b and the Evolutionary History of the System

by Keith CowingApril 5, 2024April 5, 2024

Multi-planet systems exhibit remarkable architectural diversity. However, short-period giant planets are typically isolated. Compact systems like TOI-5398, with an outer close-orbit giant and an inner small-size planet, are rare among […]

Transmission spectroscopy

Probing 2D Asymmetries Of An Exoplanet Atmosphere From Chromatic Transit Variation

Statistical Trends In JWST Transiting Exoplanet Atmospheres

Detection of H2O and CO2 in the Atmosphere of the Hot Super-Neptune WASP-166b with JWST

Astronomers Catch A Glimpse Of A Uniquely Inflated And Asymmetric Exoplanet

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

Evidence for Morning-to-Evening Limb Asymmetry on the Cool Low-Density Exoplanet WASP-107b

9 New M Dwarf Planet Candidates From TESS Including 5 Gas Giants

The PEPSI Exoplanet Transit Survey (PETS). V: New Na D Transmission Spectra Indicate A Quieter Atmosphere On HD 189733b

CRIRES+ Transmission Spectroscopy of WASP-127b. Detection Of The Resolved Signatures Of A Supersonic Equatorial Jet And Cool Poles In A Hot Planet

Orbital Obliquity of the Young Planet TOI-5398 b and the Evolutionary History of the System

NASA Planetary Protection Handbook

NASA Scientists Search For Clues About Mars’ Past In Scotland

A Temperate Sub-Neptune Transiting The M4 Dwarf TOI-210 Identified By NIRPS And TESS — Uncovering Hidden M-dwarf Planetary Systems In The Near-infrared

Nonequilibrium Formation of Pyridine (C5H5N) in Interstellar Ice Analogs: Implications for Biorelevant Nitrogen Heterocycles in Ryugu and Bennu

The Abundance And Emission Of PAHs From The Local To Early Universe