Protoplanet Archives

MRS continuum-subtracted spectra of C2H2 (magenta), HCN (green), H2O (blue), and CO2 (brown) emission lines between 13.6-15.3 µm from JDISCS sources with sub-mm dust sizes r > 63 au. ALMA images are shown to the right of the spectra (Andrews et al. 2018; Long et al. 2018, 2019a, Long et al. 2025, in prep), in order of sub-mm dust disk size from largest (top left; Elias 27, r ∼ 250 au) to smallest (bottom right; RU Lup, r ∼ 63 au). Slab model fits to the molecular emission lines are overplotted on the spectra, corresponding to the best-fit parameters and upper limits reported in Tables 5, 6, 7, and A1. 13C 12CH2 emission is also detected in the spectrum of GO Tau, along with multiple CO2 isotopologues in MY Lup (Salyk et al. 2025), and an OH-rich spectrum with no CO2 emission from GM Aur (Romero-Mirza et al., submitted). -- astro-ph.SR

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

The JDISC Survey: Linking the Physics and Chemistry of Inner and Outer Protoplanetary Disk Zones

by Keith CowingMay 13, 2025May 13, 2025

MIRI spectra of select targets from the JDISCS sample, representing broad categories of sources, namely: intermediate mass, transition disk (with a large dust cavity), solar-mass with weak water emission, solar-mass […]

The dominant phosphorous reservoirs throughout the HD 100546 disk. Left-hand panel: a map of the calculated disk temperature structure, which dictates phosphorous mineral stability. Normalised height above midplane is given by z/r, with height above midplane, z (au), divided by the radial distance, r (au). Hatched regions indicate the two dust rings identified in this system and the dotted black line marks the water iceline (parameterised simply as the 121 K isotherm after Lodders 2003). Right-hand panel: a map of the dominant phosphorous reservoirs in the disk assuming equilibrium at the dust temperature. The minerals apatite, merrillite, and schreibersite progressively replace each other as the main phoshporous reservoir as temperature is increased, up to the point where temperatures are high enough that all major phosphorous-bearing mineral phases have sublimated and most phosphorous is in the gas phase. Phosphorous dissolved in Fe metal is never a dominant reservoir, but its presence is mapped by the dashed contour. Mineral stabilties were taken from Pasek (2019). -- astro-ph.EP

Ariel Mission, Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Refractory Phosphorus In The HD 100546 Protoplanetary Disk

by Keith CowingApril 22, 2025April 22, 2025

The phosphorus budget of planets is intertwined with their formation history and is thought to influence their habitability.

Primary-subtracted images of PDS 70 in 2020 (left) and 2024 (right). North is up and East is to the left. Color scales of the two panels are identical. The expected positions of PDS 70 b and c are marked. The white dashed line marks the inner edge of PDS 70’s outer disk in infrared scattered light. PDS 70 b is detected in both epochs and demonstrates a significant orbital motion. PDS 70 c is only detected in Epoch 2024. The apparent brightness variations in PDS 70 b and c do not accurately represent the planets’ intrinsic variability, as high-contrast imaging post-processing introduces flux loss. For a comprehensive analysis of the evidence for variability, refer to Section 3.3. astro-ph.EP

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

Evidence for Variable Accretion Onto PDS 70 c and Implications for Protoplanet Detections

by Keith CowingFebruary 21, 2025

Understanding the processes of planet formation and accretion in young systems is essential to unraveling the initial conditions of planetary systems.

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

PDS 70b Shows Stellar-like Carbon-to-Oxygen Ratio

by Keith CowingNovember 25, 2024November 25, 2024

The ∼5 Myr PDS 70 is the only known system with protoplanets residing in the cavity of the circumstellar disk from which they formed, ideal for studying exoplanet formation and […]

Planetary formation -- Grok via Astrobiology.com

Astrogeology, Exoplanets, -moons, -comets, Status Report

Did The Terrestrial Planets Of The Solar System Form By Pebble Accretion?

by Keith CowingNovember 15, 2024November 15, 2024

The dominant accretion process leading to the formation of the terrestrial planets of the Solar System is a subject of intense scientific debate. Two radically different scenarios have been proposed.

The evolution of disk aspect ratio (top) and minimum planet mass required to open a gap (bottom) from young Class 0 disks (lighter colors) to mature Class II disks (darker colors) for different final protostellar masses. These models are those with small dust grains (0.1 µm). The gray dashed line presents the radius of the disk assumed in these models. The typical masses of giant and rocky planets are taken from Zhu & Dong (2021) (also see Akeson et al. 2013). Up to ∼50 M⊕ of a giant planet and an entire rocky planet would create no sign of a dust gap if formed in the protostellar phase (t < 2 × 105 yr). -- astro-ph.EP

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

If Planets Existed In Protostellar Disks They Would Hardly Produce Observable Substructures

by Keith CowingOctober 21, 2024

The onset of planet formation is actively under debate. Recent mass measurements of disks around protostars suggest an early start of planet formation in the Class 0/I disks.

Countour plot of the S/N for a 1500 K planet orbiting AD Leonis M-dwarf star (orbit of 0.13 AU) at different luminosity (y-axis) and distance (x-axis), after one hour of integration time. The horizontal yellow line indicates the current AD Leonis to sun luminosity ratio. -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Large Interferometer For Exoplanets (LIFE). XIV. Finding Terrestrial Protoplanets In The Galactic Neighborhood

by Keith CowingOctober 18, 2024October 18, 2024

The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization to distances from the solar system far greater than thermally […]

ALMA 1.3mm continuum observation of the HD 169142 system (Pérez et al. 2019), including the inferred location of the HD 169142 b protoplanet (Hammond et al. 2023). The synthesized beam is indicated by the white ellipse in the lower left. -- astro-ph.EP

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Volatile Composition Of The HD 169142 Disk And Its Embedded Planet

by Keith CowingOctober 3, 2024October 3, 2024

The composition of a planet’s atmosphere is intricately linked to the chemical makeup of the protoplanetary disk in which it formed. Determining the elemental abundances from key volatiles within disks […]

Geometrical model fit to the F480M closure phase and squared visibility data of PDS 70 (images), using uniform priors on the positions of PDS 70 b and c. With respect to the central source (yellow star), PDS 70 b is to the south-east while PDS 70 c is directly west. The white contours denote the 1, 2, 3, 4 and 5 σ contours of the marginalized posterior of the positions of PDS 70 b and c. The two grey dashed circles are centered on the predicted locations of the planets at the time of the observations (Wang et al. 2021b) from whereistheplanet (Wang et al. 2021a). We mask the central region to denote the inner working angle of ∼0.5λ/B = 94 mas, the diffraction limit of the data. -- astro-ph.EP

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

The James Webb Interferometer: Space-based Interferometric Detections of PDS 70 b and c at 4.8 μm

by Keith CowingApril 24, 2024April 24, 2024

We observed the planet-hosting system PDS 70 with the James Webb Interferometer, JWST’s Aperture Masking Interferometric (AMI) mode within NIRISS.

NIRCam images of PDS 70 obtained in the F187N (top row) and F480M (bottom row) filters using our iterative PCA algorithm. The second and third columns show the images obtained after subtraction of our outer disk model, and further subtraction of protoplanets b and c, respectively. Major and minor axes of the disk are indicated with solid and dashed lines, respectively, in the first column. Dashed circles indicate the predicted location for protoplanets b and c based on the orbital fits in Wang et al. (2021b), and for candidate d based on the orbit suggested in M19. The astrometric measurements for d (blue dots) are compared to our new estimated astrometry (solid circle) in panel c. Units are MJy sr−1. -- astro-ph.EP

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

MINDS: JWST/NIRCam Imaging Of The Protoplanetary Disk PDS 70

by Keith CowingMarch 11, 2024March 11, 2024

Context. Two protoplanets have recently been discovered within the PDS 70 protoplanetary disk. JWST/NIRCam offers a unique opportunity to characterize them and their birth environment at wavelengths difficult to access […]

Protoplanet

The JDISC Survey: Linking the Physics and Chemistry of Inner and Outer Protoplanetary Disk Zones

Refractory Phosphorus In The HD 100546 Protoplanetary Disk

Evidence for Variable Accretion Onto PDS 70 c and Implications for Protoplanet Detections

PDS 70b Shows Stellar-like Carbon-to-Oxygen Ratio

Did The Terrestrial Planets Of The Solar System Form By Pebble Accretion?

If Planets Existed In Protostellar Disks They Would Hardly Produce Observable Substructures

Large Interferometer For Exoplanets (LIFE). XIV. Finding Terrestrial Protoplanets In The Galactic Neighborhood

Volatile Composition Of The HD 169142 Disk And Its Embedded Planet

The James Webb Interferometer: Space-based Interferometric Detections of PDS 70 b and c at 4.8 μm

MINDS: JWST/NIRCam Imaging Of The Protoplanetary Disk PDS 70

Well-Preserved Polygons In Elysium Planitia on Mars

Long-term Performance Of Thermoacidophilic Methanotrophic Biotrickling Filters

Diversity Of Planetary Origins And Compositions Traced By Stellar Abundance Differences Of Co-natal Star Systems

Coupled Evolution Of Earth’s H2-rich Proto-atmosphere And Oxidized Magma Ocean

Prebiotic Synthesis of L-Homochiral Peptides on Primordial Earth