Photochemical haze Archives - Page 2 of 2 - Astrobiology

Phase folded JWST/MIRI observations of TRAPPIST-1 b. a. Phase-folded light curve of the secondary eclipse of TRAPPIST-1 b at 12.8 µm, derived from the observations of 5 eclipses as part of GTO 1279 observations. b. Phase-folded light curve of the secondary eclipse of TRAPPIST-1 b at 15 µm, derived from re-analyses of the observations of 5 eclipses as part of GTO 1177. These figures are derived from the “fiducial analysis” described in the Methods. Blue dots corresponds the corrected flux at the original time sampling, black dots shows the 10min binned corrected flux with an error equal to the standard deviation of the points within the bin, and the red curve show the eclipse model. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Combined Analysis of the 12.8 and 15 μm JWST/MIRI Eclipse Observations of TRAPPIST-1 b

by Keith CowingDecember 18, 2024December 18, 2024

The first JWST/MIRI photometric observations of TRAPPIST-1 b allowed for the detection of the thermal emission of the planet at 15 μm, suggesting that the planet could be a bare […]

The weighted abundance of CO calculated using Equation 1 has been shown as a heat map as a function of C/O and Kzz in each panel. Each row corresponds to a different Teq value from 1100 K to 600 K from top to bottom. Each column correspond to a different Tint value between 30 K and 500 K from left to right. Note that the C/O has been shown relative to the assumed solar value of 0.458 in this plot. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Ice Giant, Imaging & Spectroscopy, Neptune, Status Report

Effects of Planetary Parameters on Disequilibrium Chemistry in Irradiated Planetary Atmospheres: From Gas Giants to Sub-Neptunes

by Keith CowingOctober 23, 2024May 12, 2025

A primary goal of characterizing exoplanet atmospheres is to constrain planetary bulk properties, such as their metallicity, C/O ratio, and intrinsic heat. However, there are significant uncertainties in many aspects […]

Van Krevelen diagrams of a) 2 month old sample, b) 1.8 year old sample, c) 3.5 year old sample. The intensity of the points is given by the color code ranging from blue (lowest abundance) to red (highest abundance). Mass spectra of five different families present in the sample are given for the d) 2 month old sample, e) 1.8 year old sample, f) 3.5 year old sample. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report, Titan

Humid Evolution of Haze in the Atmosphere of Super-Earths in the Habitable Zone

by Keith CowingJune 2, 2023June 2, 2023

Photochemical hazes are expected to form and significantly contribute to the chemical and radiative balance of exoplanets with relatively moderate temperatures, possibly in the habitable zone of their host star.

Top: Abundance and temperature-pressure profiles for a 3 M⊕, 600 K equilibrium temperature planet, with 0.1% soot, orbiting an M-dwarf star. Even under the harsh UV irradiation environment of the host star, high abundances of methane (thick brown line) persist to high altitude and low pressure. A combination of methane photolysis in the upper atmosphere, vertical mixing, and thermochemistry give rise to significant quantities of higher-order hydrocarbons such as C2H2, C2H4, and C2H6, Subsequent photolysis and polymerization reactions result in the formation of hydrocarbon haze (thick dashed red line). Bottom: The resulting transmission spectrum (orange line) of this planet is shaped considerably by haze with some strong methane features permeating through the haze at longer wavelengths. The teal line shows the transmission spectrum of the same planet but with the haze opacity artificially removed, while the transparent colored line shows these data at a spectral resolution of R=1,000. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Status Report, Water/Hycean Worlds & Oceanography

Exoplanet Volatile Carbon Content as a Natural Pathway for Haze Formation

by Keith CowingMay 9, 2023May 9, 2023

We explore terrestrial planet formation with a focus on the supply of solid-state organics as the main source of volatile carbon.

Transmission spectra

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

Photochemical Hazes Can Trace The C/O Ratio In Exoplanet Atmospheres

by Keith CowingJanuary 11, 2023January 11, 2023

Photochemical hazes are suspected to obscure molecular features, such as water, from detection in the transmission spectra of exoplanets with atmospheric temperatures < 800 K.