Transmission spectroscopy Archives

Period-radius injection-recovery map for TOI 2076. Blue points indicate recovered signals, while red points mark signals that were not recovered. Only 20% of injected planets are shown for clarity. The background is color-coded by the overall completeness in a given bin. The previously known planets in the system are marked as the gold stars, TOI 2076 e is marked as the green star, and candidate TOI 2076 f is marked as the gray circle. -- astro-ph.EP

TESS Investigation -Demographics of Young Exoplanets (TI-DYE) III: An Inner Super-Earth In TOI-2076

by Keith CowingMay 13, 2025

Young (<500 Myr) multi-planet transiting systems are valuable environments for understanding planet evolution by offering an opportunity to make direct comparisons between planets from the same formation conditions.

A visual comparison of transmission spectra measured for various planets during transit (red points) and out-oftransit (black points). The p-value of an Anderson-Darling test comparing the two measurements is shown it the title of each sub-figure. The out-of-transit measurements were generated via 1000 bootstrap simulations where the white-light transit signal (see Table 3) was injected at various times of mid-transit and measured the same way as the in-transit data. The top row of planets have a calculated p-value of p < 0.05 indicating the in-transit and out-of-transit data are statistically different from one another. The bottom row of planets have p-values of p > 0.05 indicating they are not statistically dis-similar to the boot-strap simulations. For these planets we additionally compared previous measurements from the Exoplanet Archive with a flat-line using an R 2 metric. We find the previous measurements all have an R 2 < 0.54 which suggests the atmospheric signal is likely consistent with a flat line and the consistency between in-transit and out-of-transit observations may be because the spectra is naturally featureless. -- astro-ph.EP

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

Ground-Based Reconnaissance Observations Of 21 Exoplanet Atmospheres With The Exoplanet Transmission Spectroscopy Imager

by Keith CowingMarch 17, 2025September 18, 2025

One of the most prolific methods of studying exoplanet atmospheres is transmission spectroscopy, which measures the difference between the depth of an exoplanet’s transit signal at various wavelengths and attempts […]

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.

Transmission spectroscopy

TESS Investigation -Demographics of Young Exoplanets (TI-DYE) III: An Inner Super-Earth In TOI-2076

Ground-Based Reconnaissance Observations Of 21 Exoplanet Atmospheres With The Exoplanet Transmission Spectroscopy Imager

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

Early-career Graduate Students Host An Exclusive, NASA-funded Astrobiology Conference

Intimate Link Between Prebiotic Chemistry And Meteorites: Mechanisms Of Organic Molecule Formation

Microbial Mats Influence The Isotopic Composition And Provenance of Soil Organic Matter In The McMurdo Dry Valleys, Antarctica

Beyond The Prebiotic Soup: Solid Organic Films And Protocell-Like Formation in Prebiotic Discharge Experiments

From Searching For Extraterrestrial Biosignatures To Exploring The Origins Of Life: A Prebiotic Chemistry Perspective