Astronomy & Astrophysics Archives

Measured effective height of Earth’s atmosphere over the SPIRou wavelength range. The surface area, S , is derived from astrometry.

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

Earth As A Transiting Exoplanet

by Keith CowingJune 9, 2026June 10, 2026

Context. Detecting and characterizing the atmosphere of rocky planets in the habitable zone is a key objective of exoplanet research in the era of JWST and the upcoming E-ELT. Spectroscopy […]

WASP-39b transmission spectra and cloud scenarios. Spectra are observed with JWST (orange), HST (magenta), and VLT (green) in comparison to models with different Fe content: full IWF Graz cloud model (black line), Fe[s] replaced (dark gray), FeS[s] replaced (middle gray), and all Fe-binding materials replaced (light gray). The Fe-free mixed-material cloud compositions provide a good fit in the near-IR but not in the optical. — astro-ph.EP

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

Exoplanet Climate Characterization With Transit Asymmetries

by Keith CowingApril 28, 2026April 28, 2026

Context. Space missions such as CHEOPS, JWST, and PLATO facilitate detailed characterization of exoplanets, particularly close-in gas giants and their wide range of global temperatures and climate regimes.

Fully corrected and calibrated albedos of Titan (yellow), Saturn (green), Uranus (blue), and Neptune (red) covering 0.3 µm to 2.1 µm, offset for clarity. Regions of strong telluric absorption are masked in lighter shades, and it should be noted that they are less reliably corrected. The flat regions in the UV were flagged as bad pixels in all images by X-shooter. We also highlight a vertical discontinuity between the VIS and NIR arms of Titan, which is likely due to weather inconsistency. The colors used for these objects are the same in the following figures. -- Astronomy & Astrophysics

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Jupiter, Mars, Mercury, Neptune, Saturn, Status Report, Titan, Uranus

HiDef Neighbors: Solar System Objects As Exoplanet Analogs I. Gaseous Objects, Planets, Planetary Systems, And Small Bodies

by Keith CowingMarch 27, 2026

Context. Intermediate-resolution spectral observations are vital tools for characterizing the composition and physical properties of Solar System bodies in detail. At present, the planets and moons of our Solar System […]

Average difference (D ¯) between models and observations over model time (x-axis) and model density (y-axis) for the seven objects except the last panel which is for the determined best values for the objects.

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Imaging & Spectroscopy, Interstellar, Status Report

The Role Of Polycyclic Aromatic Hydrocarbons In Astrochemical Modeling At Different Evolutionary Stages Of Cold Dense Cloud Cores

by Keith CowingDecember 1, 2025December 1, 2025

Context. Although the role of PAHs have been highlighted in recent years, it is crucial to verify their functions at different evolutionary stages of dark cloud cores.

Multi-frequency imaging of PDS 70 with a zoom on the forming protoplanet PDS 70c. From left to right are the ALMA bands 4, 7, and 9. PDS70c shines in Bands 4 and 7, but not in Band 9, which can be attributed to ionized gas emission. Credit: O. Domínguez et al. – N. Lira – ALMA (ESO/NAOJ/NRAO)

Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Press Release

ALMA Pinpoints The Radio Signature Of Planetary Growth

by Keith CowingOctober 3, 2025October 3, 2025

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have obtained an unprecedented multi-frequency view of a forming planet in the nearby star system PDS 70. The new study, led by […]

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Interstellar, Radiation, Status Report

X-ray Photodesorption Of Complex Organic Molecules In Protoplanetary Disks

by Keith CowingSeptember 23, 2025September 23, 2025

Context. Nonthermal desorption from interstellar ices induced by X-rays, known as X-ray photodesorption, is a possible route to explain gas phase molecules detected in protoplanetary disks. However, the efficiency of […]

β-curves for amorphous carbon (‘C’, green lines, Kimura & Mann 1999), astronomical silicates (“SiO”, solid gold line, Gustafson 1994; and blue lines, Kimura & Mann 1999), and adapted astronomical silicates (“ad. SiO”) with an assumed dust density of ρd = 2500 kg/m3 (thick dashed maroon line; Sterken et al. 2012a). The β-curves of Kimura & Mann (1999) have porosities, p, ranging from 0% (compact particles) to 93% (fluffy particles), indicated by different line styles. (After Sterken et al. 2015, Fig. 2.) -- Astronomy & Astrophysics

Astrochemistry, Astrogeology, Astronomy & Telescopes, Comets and Asteroids, Imaging & Spectroscopy, Interstellar, Missions & Hardware, Status Report

Interstellar Dust Measured In Situ by Ulysses

by Keith CowingJuly 2, 2025July 2, 2025

Impacts of interstellar dust (ISD) grains on the Ulysses spacecraft allowed for the first successful in situ measurement of ISD (Grün et al. 1993).

CARMENES detection sensitivity map, averaged over the individual maps of the 15 stellar targets of this study. The light blue markers indicate the 11 planets included for this occurrence rate analysis, and the color map illustrates the detection probabilities of the respective periodmass grid points. The solid lines represent the masses associated to the RV semi-amplitude values equal to the RVs’ root mean square averaged over the time series (blue), the mean RV uncertainties (magenta), and the median of the RV uncertainties. -- Astronomy & Astrophysics

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

CARMENES Data: Earth-like Planets Especially Common Around Low-mass Stars

by Keith CowingJuly 1, 2025July 1, 2025

According to the latest studies led by Heidelberg University astronomers, low-mass stars quite often host Earth-like planets. Data collected as part of the CARMENES project were the basis of this […]