Protoplanetary Disk Archives

Each point shows a radius of a planet in our sample

Dynamically Selected Mass-Radius Relationship For Low Mass Exoplanets

by Keith CowingJuly 24, 2026July 24, 2026

[astro-ph.EP] We study the mass-radius relationship of planets in multiplanet systems as a function of their dynamical architecture.

The observed extreme debris disks require planet-mass collisions.

Exoplanets, -moons, -comets

Growing Planets Produce Extreme Dust Signatures

by Keith CowingJuly 21, 2026July 21, 2026

[astro-ph.EP] Collisions between planetary bodies are essential to the assembly of rocky planets like the Earth, but they are extremely difficult to observe. We therefore rely on indirect signatures of […]

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

Astrochemistry

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 […]