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Gijs D Mulders @gijsmulders.com · 12h

And finally, you can read the entire paper here, soon to be published in ApJ:
arxiv.org/abs/2509.14101

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Diversity in planetary architectures from pebble accretion: Water delivery to the habitable zone with pebble snow

"Pebble snow" describes a planet formation mechanism where icy pebbles in the outer disk reach inner planet embryos as the water ice line evolves inward. We model the effects pebble snow has on sculpt...

arxiv.org

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Gijs D Mulders @gijsmulders.com · 12h

Solar system-like architectures appear for a small range of initial disk masses around F and G stars, but are not a common feature around K and M stars.

Perhaps we are somewhat special among #exoplanets?

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Gijs D Mulders @gijsmulders.com · 12h

While the mid mass architecture is most efficient at depositing water directly in the habitable zone:

It's pebble snow!

#exoplanets
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$Water mass fraction vs disk mass for planets within the habitable zone$

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Gijs D Mulders @gijsmulders.com · 12h

The low-mass architectures are quite efficient at creating water-worlds close to the star.

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$Water mass fraction vs disk mass for planets within an orbital period of 100 days$

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Gijs D Mulders @gijsmulders.com · 12h

The architectures are remarkably consistent across stellar mass, with the location and size of planets shifting with snow line and disk mass

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The bimodel pattern in core mass vs semi-major axes is consistent across stellar mass

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Gijs D Mulders @gijsmulders.com · 12h

The mid mass architectures form a bimodal distribution:

Giant planet cores at the initial snow line location,

and a second peak with smaller, water-rich #exoplanets in the habitable zone!

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Mid mass architecture with giant planet cores at the snow line and water-rich smaller planets in the habitable zone

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Gijs D Mulders @gijsmulders.com · 12h

And…

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Gijs D Mulders @gijsmulders.com · 12h

Low mass disks from predominantly planetary cores closer in, possible precursors to super-earths or waterworlds.

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Low mass architecture with watery super-earth cores growing inside of the snow line

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Gijs D Mulders @gijsmulders.com · 12h

The main results is there are three growth modes:

High mass disks form exclusively giant planet cores outside the snow line

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High mass architecture with planet cores growing outside of the snow line

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Gijs D Mulders @gijsmulders.com · 12h

And explored a large range of stellar mass and disk mass to identify trends

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$Snow line locations for different stellar masses and disk mass fractions$

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Gijs D Mulders @gijsmulders.com · 12h

And a snow line that moves in over time

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Plot of planet core mass vs semi-major axis with 50 planetary seeds and a moving snow line

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Gijs D Mulders @gijsmulders.com · 12h

Sean added two components:

Pebble filtering from 100s of planetary cores growing simultaneously

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Plot of planet core mass vs semi-major axis with 100 planetary seeds

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Gijs D Mulders @gijsmulders.com · 12h

And the code from Ormel & Liu 2018 that calculates planet growth from the pebble flux.
i.astro.tsinghua.edu.cn/~cormel/NewS...

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Chris Ormel's research page

i.astro.tsinghua.edu.cn

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Gijs D Mulders @gijsmulders.com · 12h

PPOL is an amalgam of Pebble Predictor, a code that models the flow of pebbles through the disk
github.com/astrojoanna/...

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GitHub - astrojoanna/pebble-predictor: Predicts Stokes number and pebble flux in a smooth protoplanetary disk

Predicts Stokes number and pebble flux in a smooth protoplanetary disk - astrojoanna/pebble-predictor

github.com

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Gijs D Mulders @gijsmulders.com · 12h

To address this question University of North Dakota graduate Sean McCloat created the PPOLs model
github.com/spmccloat/th...
spmccloat.github.io/thePPOLSmode...

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GitHub - spmccloat/thePPOLSmodel: Code and docs for planet accretion via pebble snow model.

Code and docs for planet accretion via pebble snow model. - spmccloat/thePPOLSmodel

github.com

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Gijs D Mulders @gijsmulders.com · 12h

How would the diverse population of giants planets discovered around other stars, impact the mass and water content of exoplanets in the habitable zone?

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Diverse population of giant (exo)planets

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Gijs D Mulders @gijsmulders.com · 12h

Jupiter has long been suspected to play as role in shaping the inner solar system and controlling water delivery to earth

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Jupiter with impact marks from comet Shoemaker/Levy

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Gijs D Mulders @gijsmulders.com · 12h

One of the big mysterious in planet formation is how earth got to its current state:

Not too big or too small, and with the right amount of water to support life.

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$Earth with a small mass fraction of water, shown as a sphere$

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Gijs D Mulders @gijsmulders.com · 12h

How do giant planets influence the type of #exoplanets that form in the habitable zone?

A thread 1/🧵

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Reposted by Gijs D Mulders

András Gáspár @andrasgaspar.bsky.social · 9d

Our paper on the JWST/MIRI observations of the epsilon Eridani system, led by Dr. Schuyler Wolff, were published today! This is the last of the Archetypical Disks in our MIRI Survey, after Fomalhaut and Vega. Just like for those disks, our MIRI images reveal an extended inner asteroid disk!

Four color image of the eps Eri debris disk.

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Reposted by Gijs D Mulders

Jonathan Fortney @jjfplanet.bsky.social · 13d

I'm really excited about this one! It's fantastic working with Dr. Yayaati Chachan:
arxiv.org/abs/2509.20428
"Revising the Giant Planet Mass-Metallicity Relation: Deciphering the Formation Sequence of Giant Planets"
Lots of great nuggets her, including that even super-Jupiters are very metal-rich.

Revising the Giant Planet Mass-Metallicity Relation: Deciphering the Formation Sequence of Giant Planets

The rate at which giant planets accumulate solids and gas is a critical component of planet formation models, yet it is extremely challenging to predict from first principles. Characterizing the heavy...

arxiv.org

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Reposted by Gijs D Mulders

Dr. Jessie Christiansen @aussiastronomer.bsky.social · 21d

Sometimes 2025 just feels like a lot, and you need an excuse to celebrate your fabulous team (and the whole exoplanet community!) reaching a new milestone…

Happy 6,000 Confirmed Exoplanets Day, everybody!!!!

(You may recognize the narrator of the video at the link! 🫣)

www.nasa.gov/universe/exo...

A close-up photo of a box of cupcakes with gold candles spelling out ‘6000’.

A group of smiling people - scientists, engineers, data analysts and writers - standing behind a table of goodies.

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Reposted by Gijs D Mulders

Adam Rains @spectraltypos.bsky.social · 21d

Paper day!

You're doing ground-based high-resolution exoplanet transmission spectroscopy and want to analyse the planet—not the star or Earth's atmosphere.

Is there a way to disentangle your spectrum *without* destroying the planet signal?

arxiv.org/abs/2509.12737

🧵⬇️

🔭 #exoplanets #astromethods

TSD: An inverse problem approach for recovering the exoplanetary atmosphere transmission spectrum from high-resolution spectroscopy

Our ability to observe, detect, and characterize exoplanetary atmospheres has grown by leaps and bounds over the last 20 years, aided largely by developments in astronomical instrumentation; improveme...

arxiv.org

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Reposted by Gijs D Mulders

Emily Hunt @emily.space · Sep 8

For the last two years, I've been paying for the Astronomy feeds hosting myself.

It has been a privilege to grow our community here, but I also shouldn't keep doing it for free 😅

That's why I'm delighted to announce that we now have a donations page on Open Collective! 🔭☄️ #astrophotography

The Astrosky Ecosystem - Open Collective

We're building an open-source ecosystem of social media tools for the space science & astronomy communities.

opencollective.com

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Reposted by Gijs D Mulders

Melina Thévenot🏳️‍⚧️ @melina-iras07572.bsky.social · Sep 3

Seems like Ayumu Shoshi et al. did take a high-resolution ALMA image of the disk around IRAS 04125+2902. arxiv.org/abs/2509.01896

This system also has the youngest transiting #exoplanet, discovered in November 2024 with TESS.

Disk, planet orbit and outer stellar companion orbit are all misaligned.

Figure 1 of the pre-print. Three images of the same dust ring using different methods.

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