Protoplanetary Disk Archives

Integrated MIRI-MRS spectrum of HK Tau A (top) and B (bottom) in grey, with the black line representing the continuum baseline. In the top panel, the insets zoom into wavelength regions where molecular emission from 12CO, H2O, 12CO2 , and H2 is visible. In the bottom panel, the shaded bands in the indicate the main ices absorption regions. H2 rotational lines are marked with blue ticks, and gas emission features are labelled where present. -- astro-ph.EP

MINDS: Complementary Inclinations In The Binary Ssystem HK Tau Reveal Gas- And Ice-phase Chemistry

by Keith CowingJuly 7, 2026July 7, 2026

[astro-ph.EP] HK Tau is a roughly equal mass pre-main sequence binary system consisting of a low-inclination primary (57 deg) and an edge-on (83 deg) secondary. We present JWST/MIRI observations targeting […]

Envelope compositions obtained in this study.

Exoplanets, -moons, -comets

Planet Formation In Chemically Diverse And Evolving Discs II. Chemical Fingerprints In Planetary Atmospheres

by Keith CowingJuly 6, 2026July 6, 2026

[astro-ph.EP] Giant planets form in protoplanetary discs, where the coupled dynamical and chemical evolution of gas and solids determines the composition of the material they accrete. We investigate how planet […]

[LEFT] Evolution of the fiducial full 2D simulation. The simulation has run for ∼ 4 Myr; line opacity increases with time in intervals of 0.4 Myr. The top row shows the surface densities of dust (ice included), ice and vapour, whilst the second row shows the mid-plane temperature. The small noncontinuous deviations in the surface density appear due to integration over the tightly-constrained, discontinuous vertical structure of the ice. [RIGHT] Spatial distributions of CO ice and vapour density in the full 2D fiducial simulation. Temperature contours (in K) are over-plotted for reference. -- astro-ph.EP

Astrochemistry

CO Snow Lines Are Stabilised By The Vertical Transport Of Volatiles

by Keith CowingJuly 5, 2026July 5, 2026

[astro-ph.EP] Volatile evolution in protoplanetary discs determines the compositional evolution of forming planets. Below their sublimation temperatures, volatiles freeze out from the vapour phase onto dust grains in the disc […]

Sketch of the dust grain growth and disk structure. The physical processes, observational tech- niques, and disk components depicted are described in Sect. 1. The horizontal axis in the upper panel repre- sents increasing particle size (and implicitly evolutionary time), from micron-sized grains to planetary cores. The disk in the sketch coarsely extends to 30–100 au. The inner part highlights the motion of the ionized gas at (sub-)au scale toward the star following the magnetic field. -- astro-ph.EP

Exoplanets, -moons, -comets

Demographics Of Planet-forming Disks With The SKAO

by Keith CowingJuly 3, 2026July 3, 2026

[astro-ph.EP] Understanding how solid material in planet-forming disks evolves from micron-sized dust to planetary cores is a central challenge in modern astrophysics. This study has advanced dramatically in the past […]

Figure summarizing the key science objectives. -- astro-ph.IM

Exoplanets, -moons, -comets

Nautilus Space Observatory: The Evolution of Planets and their Atmospheres

by Keith CowingJune 29, 2026June 29, 2026

[astro-ph.IM] We are just beginning to explore the billion-year evolution from nascent planets in disks to mature planetary systems. Recent discoveries hint at demographic and atmospheric differences between young planets […]

Light curves of HIP 41378. Upper panel: K2 C5 campaign (long cadence). Bottom panel: K2 C18 campaign (short cadence). The pink curve represents the median of the best-fit model from photometry and RV analysis. The names of the planets are highlighted with their letters. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy

A Decade Of Monitoring The HIP 41378’s Planetary System

by Keith CowingJune 25, 2026June 25, 2026

Multi-planetary systems provide key constraints on planet formation and evolution, as their architecture encodes the dynamical history of planets formed within a common protoplanetary disk.

Exoplanet 29 Cygni b, seen in this artist’s concept, is a gas giant weighing about 15 times the mass of Jupiter. It orbits a type A star (shown at upper right) slightly hotter and more massive than our Sun, at an average distance of 1.5 billion miles. The star is known to possess a dusty debris disk. A hypothetical comet fragment is shown approaching the planet, while previous impacts have left dark splotches on its cloudtops, similar to what was seen from the Shoemaker-Levy 9 impact on Jupiter in our solar system. -- NASA Larger image

Astrogeology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release, Stellar Cartography

Webb Redefines The Dividing Line Between Planets And Stars

by Keith CowingJune 16, 2026June 16, 2026

Planets, like those in our solar system, form in a bottom-up process where small bits of rock and ice clump together and grow larger over time. But the heftier the […]

Carbon isotope ratio as a function of the semi-major axis for young, directly-imaged companions. Measurements in the HR 8799 system for planets e, b, and c (Ruffio et al. 2026) are shown with squares and connected with a dotted line. The other measurements are for HD 984 b (Costes et al. 2024), GQ Lup b (González Picos et al. 2025b), VHS 1256 b (Gandhi et al. 2023), YSES 1 b (Zhang et al. 2024), AB Pic b (Gandhi et al. 2025), and DH Tau b and HIP 79098 b (Xuan et al. 2024a). The present-day local ISM (12C/13C = 68±14; Milam et al. 2005) and solar photospheric value (12C/13C⊙ = 91.4 ± 1.3; Lyons et al. 2018) are overlaid. The horizontal line spans the typical CO snow-line location for a solar-type host star (22–36 au). For stars hotter than the Sun, the CO snow line is expected at distances greater than 30 au, so β Pic b is located interior to the CO snow line. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

The Carbon Isotope Ratio Of β Pic b With High-resolution Spectroscopy

by Keith CowingJune 13, 2026June 13, 2026

Isotopic ratios trace the formation and evolution of planets and link their atmospheres to the chemistry of their natal protoplanetary discs.

Left: Qϕ image of WRAY 15-1880 obtained from the SPHERE polarimetric data. The red dot at the center of the image marks the position of the star; the dashed white circle is the size of the coronagraph used in this observation. The dotted straight lines mark the major and minor axes, as obtained by Curone et al. (2025). Right: similar image, but projected on the disk plane (i “ 39.22 deg) and rotated to have the major axis vertical and the minor axis horizontal. On this plane, the coronagraphic mask is an ellipse represented by the white dashed line. The yellow circle has a radius of 214.1 mas that is the peak of the disk as determined by the ALMA data (see Section 3.3.2). The center of this circle has been offset by 37 mas along the minor axis, to fit the outer contour of the observed disk East of the star, that is the closest side of the disk. The red solid circle (radius of 110 mas) fits the feature seen north of the star. The position of the planet discussed in Section 3.2 at the epoch of the SPHERE polarimetric observation is marked with a small white circle, and its orbit is shown as magenta circle. -- astro-ph.SR

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

Analysis Of The Young Disk Around WRAY 15-1880: Does It Contain A Primitive Planetary System?

by Keith CowingJune 11, 2026June 11, 2026

Observations of (giant) planets accreting material within their natal environment are crucial to constrain models for their formation.

Optical depth spectrum and ENIIGMA best-fit model for the 4.0-4.45 µm region and its separate components. Major gas lines are labeled. The inset zooms in on the HDO ice feature. -- astro-ph.EP

Astrochemistry, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Interstellar, Press Release, Water/Hycean Worlds & Oceanography

First Detection Of HDO Ice In A Protoplanetary Disk

by Keith CowingJune 11, 2026June 11, 2026

Protoplanetary disks are the birthplace of planets and planetary systems. Investigating the molecular inventory of disks is key to linking the chemical evolution of the interstellar medium and the makeup […]

Protoplanetary Disk

MINDS: Complementary Inclinations In The Binary Ssystem HK Tau Reveal Gas- And Ice-phase Chemistry

Planet Formation In Chemically Diverse And Evolving Discs II. Chemical Fingerprints In Planetary Atmospheres

CO Snow Lines Are Stabilised By The Vertical Transport Of Volatiles

Demographics Of Planet-forming Disks With The SKAO

Nautilus Space Observatory: The Evolution of Planets and their Atmospheres

A Decade Of Monitoring The HIP 41378’s Planetary System

Webb Redefines The Dividing Line Between Planets And Stars

The Carbon Isotope Ratio Of β Pic b With High-resolution Spectroscopy

Analysis Of The Young Disk Around WRAY 15-1880: Does It Contain A Primitive Planetary System?

First Detection Of HDO Ice In A Protoplanetary Disk

NASA Spaceline Current Awareness List #1,206 2 July 2026 (Space Life Science Research Results)

Older Than The Sun: Astronomers Find New Clues To The Origin Of Interstellar Comet 3I/ATLAS

Carl Sagan Month: Call For Participation

The Habitable Worlds Observatory Technology Development Plan

Searching For The Elusive CH2+ With The James Webb Space Telescope. Another Carbocation To Constrain Astrochemical Networks