The Astrophysical Journal Archives

Artist’s concept of a star and its debris disc against the black background of space. The star is in the background, right of center, and depicted as a small, luminous sphere. Credit: NASA, ESA, CSA, J. Olmsted (STScI)

JWST Studies Of Planet-shattering Collisions

by Keith CowingOctober 2, 2026October 2, 2026

[ESA]. In the early history of our Solar System, a Mars-sized object called Theia smashed into the infant Earth, vapourising massive amounts of rock and blasting it into space. Some […]

Exoplanets, -moons, -comets

Large Planets Ruled Out After 70 Ophiuchi AB Binary System Search

by Keith CowingSeptember 30, 2026September 30, 2026

[University of Michigan] New research led by the University of Michigan is helping set the stage for future observatories to characterize rocky planets outside our solar system, planets that could […]

ESO/L. Calçada/P. Delorme/Nick Risinger (skysurvey.org)/R. Saito/VVV Consortium via NASA Larger image

Exoplanets, -moons, -comets

Free Floating Exoplanets or Merely Detached?

by Keith CowingJuly 1, 2026July 1, 2026

[Astrophysical Journal] Microlensing surveys suggest the presence of a surprisingly large population of free-floating planets, with a rate of about two Neptunes per star.

A three-color image of the CygX region constructed from SPHEREx mosaics. In this image, blue is 1.13–1.19 μm, green is 2.9–3.20 μm (containing the H2O ice absorption feature), and red is 4.75–5.1 μm. Continuum emission from warm dust extends across the image, as evidenced by the extended orange clouds. Dark lanes are seen where the dust and H2O ice absorption are the strongest. Red sources appear in these dark lanes where there are background sources or embedded young stars shining through the dust. Blue stars are seen in regions with lower extinction or are foreground objects. -- The Astrophysical Journal

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

Astrochemistry Update: SPHEREx Maps Vast Galactic Ice Regions

by Keith CowingApril 15, 2026April 15, 2026

NASA’s SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) mission has mapped interstellar ice at an unprecedented scale.

Set of iCOMs considered in this work. Color code: red for oxygen, white for hydrogen, gray for carbon, and blue for nitrogen. -- The Astrophysical Journal

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

Binding Energies of Interstellar Complex Organic Molecules on Water Ice Surfaces: A Quantum Chemical Investigation

by Keith CowingNovember 10, 2025November 10, 2025

Interstellar dust grains are enveloped by ices of frozen molecules in cold, dense regions of the interstellar medium (ISM), which are also observed in the gas phase.

Cross-correlation function significance plotted as a function of planet velocity amplitude and systemic radial velocity. The significance is the number of standard deviations above the mean for those parameters, peaking at 5.7σ. -- The Astrophysical Journal

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

CO Detected in CI Tau b: Hot Start Implied by Planet Mass and MK

by Keith CowingOctober 30, 2025October 30, 2025

We acquired high-resolution infrared spectra of CI Tau, the host star of one of the few young planet candidates amenable to direct spectroscopic detection.

Figure reproduced from H. Toru Shay et al. (2025). The detected inventory of TMC–1 molecular species and their column densities is converted into numerical vectors with the VICGAE model. The vectorized strings and the corresponding column densities are then used to train a machine learning regressor. Through learning the relationship between vectorized molecular structures and their column densities, the model is optimized to find the best fit. Once trained, the best-fit model can predict column densities for new molecules and be used to identify potential detection targets in TMC–1. -- The Astrophysical Journal

AI - Data - Apps - Cybernetics, Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Bridging Machine Learning and Spectroscopy: A New Analysis for Astrochemical Target Selection

by Keith CowingOctober 27, 2025October 27, 2025

In the last few years, several approaches have used machine learning to reproduce the inventory and column densities of interstellar molecular sources.

Reflected total normalized flux πFn (left panel) and signed degree of linear polarization Ps (right panel) as functions of the planetary phase angle α and wavelength λ for our Hadean: Moon model. Note the differences in the color bars for the two plots. -- The Astrophysical Journal

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

Polarized Signatures of the Earth Through Time: An Outlook for the Habitable Worlds Observatory

by Keith CowingApril 20, 2025April 20, 2025

The search for life beyond the solar system remains a primary goal of current and near-future missions, including NASA’s upcoming Habitable Worlds Observatory (HWO).

Left: color composite image of 114–426 using the F115W and F140M (both blue), F162M (green), F182M (yellow–green), and F277W (red) bands. Each of the four SW channel images (F115W, F140M, F162M, and F182M) were interpolated onto a 3 × 3 pixel subgrid (i.e., roughly 10 mas pixel−1) to allow precise alignment, and the LW channel image (F277W) was resampled to match. Right: an image of 114–426 in the F187N band, again interpolated onto a 3 × 3 pixel subgrid, showing the silhouette disk in maximum contrast against the Paα line. Each panel is 35 × 35 with north up and east left. The intensity of each image was scaled logarithmically to compress the dynamic range and enhance fainter details. -- The Astrophysical Journal

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Water Ice in the Edge-on Orion Silhouette Disk 114–426 from JWST NIRCam Images

by Keith CowingFebruary 23, 2025February 23, 2025

We examine images of the protoplanetary disk 114–426 with JWST/NIRCam in 12 bands. This large disk is oriented edge on with a dark midplane flanked by lobes of scattered light.

Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Setting The Stage For The Search For Life With The Habitable Worlds Observatory: Properties Of 164 Promising Planet-survey Targets

by Keith CowingJuly 18, 2024August 2, 2024

The Decadal Survey on Astronomy and Astrophysics 2020 has recommended that NASA realize a large IR/optical/UV space telescope optimized for high-contrast imaging and spectroscopy of ∼25 exo-Earths and transformative general […]