Gijs D Mulders
@gijsmulders.com
📤 305
📥 59
📝 97
Exoplanet Astronomy Assistant Professor Santiago de Chile
http://gijs.cl
\m/
pinned post!
Why does the solar system not have super-Earths? A thread
#exoplanets
☄️
7 months ago
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Gijs D Mulders
Dr. Emily Gilbert
28 days ago
It's happening!!! Pandora is going to space in just over 16 hours (if all goes well). Pandora is going to help us study exoplanet atmospheres, even when their host stars are misbehaving. I am headed up to Vandenberg to watch the launch shortly, and will make a thread about the mission/launch here!
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Emily Hunt
about 2 months ago
Ever wondered how many bins to choose when making a histogram of data? The answer is that you shouldn't choose a number of bins yourself! ☄️
#astrocode
Here's a little notebook explaining how to make less biased histograms:
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Making histograms is a common way to estimate the true density distribution of a sample. But how can we choose the number of histogram bins? And if we get fancy and use kernel density estimation (KDE)...
Making histograms is a common way to estimate the true density distribution of a sample. But how can we choose the number of histogram bins? And if we get fancy and use kernel density estimation (K...
https://gist.github.com/emilyhunt/f656ac05e42e32efa723df7e741b006f
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Gijs D Mulders
Dennis Just 🌵
about 2 months ago
I'm very happy I woke up at 4am this morning to catch 3I/ATLAS right before its closest approach to Earth (today!) This interstellar visitor is traveling over 60 km/s ☄️ At 269 million km (1.8 AU), I took a series of 2.5 min exposures with my Seestar 🔭
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Bibiana Prinoth
about 2 months ago
The application for the ESO Summer Research Programme 2026 has just opened! It‘s a six week programme in Garching close to Munich where pre-Ph.D students can work on a hands-on project. Working at
@eso.org
is a fabulous experience, so please help me spread the word ✨ 🔗
eso.org/sci/meetings...
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ESO - SummerResearch2026
ESO is the European Organisation for Astronomical Research in the Southern Hemisphere. It operates the La Silla Paranal Observatory in Chile and has its headquarters in Garching, near Munich, Germany.
https://eso.org/sci/meetings/2026/SummerResearch2026.html
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seven rasmussen
about 2 months ago
the day is finally here: you can order my debut non-fiction, CLOUDY WITH A CHANCE OF STARSHIPS: HOW THE DRAKE EQUATION REVEALS THE ODDS OF LIFE IN THE COSMOS from B&N!!
www.barnesandnoble.com/w/cloudy-wit...
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Sera Markoff
about 2 months ago
⭐️✨🔭Please help us get the message out about the 7th annual international ASPIRE program at
@api.uva.nl
. This summer 2026 school provides astronomy research experience for talented MSc students from countries where opportunities to move into a PhD program are limited. Applications are due 17 Dec! ⭐️✨🔭
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ASPIRE
https://aspire.science.uva.nl/
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Equating giant planet occurrence rate of ~20% to the disk fraction, that means a timescale of ~10 Myr for giant planet formation!
add a skeleton here at some point
2 months ago
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Gijs D Mulders
Emily Hunt
2 months ago
New paper led by Fabian Polnitzcky & with
@sratzenboeck.bsky.social
+
@joaoalves.bsky.social
: based on the ages of stars with infrared excess in Sco-Cen, it seems planet-forming disks last around twice as long as previous estimates suggest - giving twice as long for planets to form. 🔭☄️
#exoplanets
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Question for the
#exoplanets
crowd: Does any one know where to find an updated version of this plot? I'm looking for the "standard" exoplanet mass vs. semi-major axis plot, but with an overlay of which planets have a spectroscopic measurement of their atmosphere
wasp-planets.net/2020/09/29/w...
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Which exoplanets do we have atmospheric spectra for?
Here’s an interesting plot created by Zafar Rustamkulov (@exoZafar), a PhD student at Johns Hopkins University. He has added up all the exoplanets for which we have either transmission spectr…
https://wasp-planets.net/2020/09/29/which-exoplanets-do-we-have-atmospheric-spectra-for/
3 months ago
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Gijs D Mulders
Ilaria Pascucci
3 months ago
Enjoyed giving a UofA Origins talk on how protoplanetary disks evolve – featuring new results from ALMA and JWST. The recording is available here 👇
youtu.be/mdgGgnjVbb0
@uarizonalpl.bsky.social
@stewardobservatory.bsky.social
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Protoplanetary Disk Evolution in the ALMA–JWST Era (Ilaria Pascucci, UArizona/LPL)
YouTube video by Origins Seminars
https://youtu.be/mdgGgnjVbb0
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Gijs D Mulders
Eric Mamajek
3 months ago
Big congrats to Jennifer Burt, Xavier Dumusque, and Sam Halverson on finishing their epic (instant classic) Annual Reviews of Astronomy & Astrophysics article "Precise Radial Velocities"!
arxiv.org/abs/2511.01954
contains some great new graphics for talks on
#exoplanets
#EPRV
#DopplerSpectroscopy
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Gijs D Mulders
Kevin Hardegree-Ullman
4 months ago
The NASA
#Exoplanet
Archive now has Gaia DR3 IDs! This should hopefully make your work and planning observations easier!
exoplanetarchive.ipac.caltech.edu
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Gijs D Mulders
Tim Lichtenberg
4 months ago
w/ Oli Shorttle,
@johannateske.bsky.social
& Eliza Kempton we reviewed our current understanding and prospects for peaking on the inside of small
#exoplanets
in "Constraining exoplanet interiors using observations of their atmospheres":
www.science.org/stoken/autho...
&
arxiv.org/abs/2510.08844
🔭🧪⚒️☄️
add a skeleton here at some point
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How do giant planets influence the type of
#exoplanets
that form in the habitable zone? A thread 1/🧵
4 months ago
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Gijs D Mulders
András Gáspár
4 months ago
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!
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Gijs D Mulders
Jonathan Fortney
4 months ago
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.
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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...
https://arxiv.org/abs/2509.20428
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Gijs D Mulders
Dr. Jessie Christiansen
5 months ago
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...
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Adam Rains
5 months ago
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
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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...
https://arxiv.org/abs/2509.12737
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Gijs D Mulders
Emily Hunt
5 months ago
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
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The Astrosky Ecosystem - Open Collective
We're building an open-source ecosystem of social media tools for the space science & astronomy communities.
https://opencollective.com/the-astrosky-ecosystem
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Gijs D Mulders
Melina Thévenot🏳️⚧️
5 months ago
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.
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Gijs D Mulders
Matthew Kenworthy
6 months ago
Proud supervisor moment: #LeidenObservatory graduate student Richelle van Capelleveen led one of two papers on our
discovery of WISPIT 2b
#LeidenObservatory
a 5 Jupiter mass exoplanet clearing a path in a circumstellar disk. Laird Close and his team saw it in H-alpha, indicating gas accretion
#astrodon
🔭 🧪
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Gijs D Mulders
Gabe Weible
5 months ago
New protoplanet(s?) alert! I'm happy to share this LBTI image of WISPIT 2 from our team's paper led by Laird Close. Planet b was discovered at Hα with MagAO-X following the SPHERE disk discovery (R. van Capelleveen +), and CC1 might be a candidate 2nd (enshrouded?) protoplanet
#exoplanets
☄️🔭🧪
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#achievement
for the day (please don't send me any more email)
6 months ago
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Gijs D Mulders
Jonathan Fortney
6 months ago
I think that mass-loss is important for sub-Neptunes and the "radius valley," but I do not think that "core-powered" escape is significant. We find that "Boil-off," right when the disk dissipates, and then XUV driven escape, are major influences.
ui.adsabs.harvard.edu/abs/2024ApJ....
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https://ui.adsabs.harvard.edu/abs/2024ApJ...976..221T/abstract
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Question for the radial velocity
#exoplanets
experts: Is there an animation that shows two spectra being shifted with respect to each other and the corresponding values of the cross correlation function changing? I think I’ve seen one in a talk but can’t find a nice animation online
6 months ago
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Gijs D Mulders
Dr Ryan MacDonald
6 months ago
We looked for an atmosphere on TRAPPIST-1d using JWST, but we didn't see any atmospheric absorption. So TRAPPIST-1d is quite different from Earth, despite lying just inside the habitable zone. The planet is either: ➡️ A bare rock. ➡️ Very cloudy. ➡️ Has a thin, Mars-like atmosphere.
#Exoplanets
🔭
add a skeleton here at some point
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Kevin Hardegree-Ullman
6 months ago
Kepler mission: smaller stars have more short-period, small
#exoplanets
. Theory: the smallest stars won’t have enough disk material to make small planets so there must be a turnover. Kepler+K2: We have found a turnover! Check out our newest Scaling K2 paper:
arxiv.org/abs/2508.05734
🧵 1/9 🔭🧪☄️
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Scaling K2 VIII: Short-Period Sub-Neptune Occurrence Rates Peak Around Early-Type M Dwarfs
We uniformly combined data from the NASA Kepler and K2 missions to compute planet occurrence rates across the entire FGK and M dwarf stellar range. The K2 mission, driven by targets selected by guest ...
https://arxiv.org/abs/2508.05734
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Gijs D Mulders
Steve Desch
6 months ago
I have a complaint about Avi Loeb's latest work and I want to speak to management.
medium.com/@steve.desch...
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This is not the quality of pseudoscience infotainment to which I have grown accustomed
Teasing the public with fraudulent or self-deluded promises of aliens used to mean something. It took work. It meant slapping together…
https://medium.com/@steve.desch/this-is-not-the-quality-of-pseudoscience-infotainment-to-which-i-have-grown-accustomed-34268f892ba8
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Dr. Jessie Christiansen
6 months ago
Images from Palomar at 2 different infrared wavelengths last night - one that Saturn's methane atmosphere absorbs, and one the it reflects! (The faint point source is the moon, Tethys!) Taken by David Ciardi, Catherine Clark,
@lowbacca.bsky.social
and Miranda Felsmann; animated by me (and ezgif!)
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Dr. Jessie Christiansen
6 months ago
I really like this graphical summary of the architectures of planetary systems from
@sidereuskinch.bsky.social
's talk at From Transits to Trends!
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Gijs D Mulders
David Kipping
7 months ago
New paper! Allow me to introduce TARS = Torqued Accelerator using Radiation from the Sun. TARS (yes inspired by Interstellar!) is a rotating light sail that's capable of launching chip sats into interstellar space using only radiation from the Sun, so let's dive into how it works.
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Dr. Jessie Christiansen
7 months ago
The main takeaway of my talk, in the style of the ‘Behold my field of fucks and see that it is barren’ embroidery:
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Gijs D Mulders
Harshitha M Parashivamurthy
7 months ago
What does the radius valley tell about the planet formation scenario around low mass stars? And how does it connect it with water worlds? To know more, come visit my poster #37 at SSW2025.
#sagan2025
#exoplanets
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Gijs D Mulders
Greg Gilbert
7 months ago
Want to learn about the relationship between planet size and orbital eccentricity? Read this thread! 🧪 🔭 🪐
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Gijs D Mulders
Institute of Astrophysics UC
7 months ago
Earn Your PhD at Earth's Premier Astronomy Hub! 🔭 ✅ Study under world-renown scientists ✅ Access legendary telescopes ✅ Join a global research network 🔗 Apply now:
astro.uc.cl/en/doctorado...
📅 Application period: From July 1st to August 1st, 2025 for March 2026 intake.
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Interested in doing a Masters or PhD in one of the leading astronomical institutes in Latin America? Apply now to these fully funded positions!
aas.org/jobregister/...
🔭🧪☄️
#exoplanets
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PhD and Master positions in Astrophysics at Pontificia Universidad Católica de Chile | American Astronomical Society
The Institute of Astrophysics at Pontificia Universidad Católica de Chile (IA-PUC) invites applications to our Ph.D. (4-yr) and Master’s (2-yr) programs, beginning March 2026, from talented students w...
https://aas.org/jobregister/ad/57236ddd
7 months ago
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Why does the solar system not have super-Earths? A thread
#exoplanets
☄️
7 months ago
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Gijs D Mulders
Emily Hunt
8 months ago
More on DR4: it's expected to include "a few thousand" exoplanets, potentially doubling or tripping the number of known exoplanets! ☄️
#exoplanets
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Gijs D Mulders
Emily Hunt
8 months ago
Finding out about Gaia at
#EAS2025Cork
! ☄️ Just announced: Gaia DR4 will be released in December 2026!
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Dr. Jessie Christiansen
8 months ago
#exoplanets
#jobs
📣 I'm advertising for a postdoc! Come work with me in sunny SoCal on the Roman Galactic Exoplanet Survey Project Infrastructure Team. You'll help build the pipeline for Roman* occurrence rates. *Launches NEXT YEAR! Please RT & share with your networks!
aas.org/jobregister/...
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Postdoctoral Scholar - Roman Galactic Exoplanet Survey PIT | American Astronomical Society
IPAC, part of the Physics, Math, and Astronomy Division at Caltech, provides science operations, user support, data and archive services, and scientific vision to maximize discovery with observatories...
https://aas.org/jobregister/ad/a3fe5316
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Ilaria Pascucci
8 months ago
Twelve ALMA/AGE-PRO papers just out! Exploring how gas and dust evolve in disks 🌟🌀 — Congrats to all authors! 🎉 NRAO press release:
public.nrao.edu/news/alma-pl...
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Gijs D Mulders
Astrobites
8 months ago
From Kaz Gary: For Pride Month, Astrobites is interviewing one transgender astronomer every week. This week we interviewed Dr. Eliot Halley Vrijmoet, a postdoctoral fellow at Smith College! 🔭✨☄️
astrobites.org/2025/06/06/e...
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Transgender in Astronomy: Interview with Dr. Eliot Halley Vrijmoet
For Pride Month, Astrobites is interviewing one transgender astronomer every week. This week we interviewed Dr. Eliot Halley Vrijmoet, a postdoctoral fellow at Smith College!
https://astrobites.org/2025/06/06/eliot-vrijmoet-interview/
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Dr. Jessie Christiansen
8 months ago
Hey, the paper is online! 🎉🪐🔭
#exoplanet
Check out the shiny new NASA Exoplanet Archive and ExoFOP paper, which covers all the updates to our data and services since Akeson+2013. Please update your .bib files and cite accordingly!!
arxiv.org/abs/2506.03299
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The NASA Exoplanet Archive and Exoplanet Follow-up Observing Program: Data, Tools, and Usage
The NASA Exoplanet Archive and the Exoplanet Follow-up Observing Program service are two widely used resources for the exoplanet community. The NASA Exoplanet Archive provides a complete and accurate ...
https://arxiv.org/abs/2506.03299
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Gijs D Mulders
Dr. Jessie Christiansen
9 months ago
Fewer than 100 planets to go! 👀🪐🔭✨
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Reboost for
#astronomy
and
#exoplanet
feed 🔭☄️🪐
add a skeleton here at some point
9 months ago
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Reboost for the
#astronomy
feed
add a skeleton here at some point
9 months ago
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Gijs D Mulders
Institute of Astrophysics UC
9 months ago
Now hiring: 2 Tenure‑Track Faculty Positions | Institute of Astrophysics, Pontificia Universidad Católica de Chile (PUC) – Santiago, Chile 🇨🇱 Full details & submission:
astro.uc.cl/en/noticias/...
#FacultyPosition
#Astrophysics
#AcademicJobs
#ResearchCareers
#PUC
#Chile
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Gijs D Mulders
Chris Lintott
9 months ago
A new, thorough reanalysis of the data that led to claims of biosignatures on K2-18b from
@luiswel.bsky.social
& friends - a nicely written lesson on why this stuff is hard. They find no significant evidence for DMS, the gas the Cambridge team claimed to have found.
arxiv.org/abs/2504.21788
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The Challenges of Detecting Gases in Exoplanet Atmospheres
Claims of detections of gases in exoplanet atmospheres often rely on comparisons between models including and excluding specific chemical species. However, the space of molecular combinations availabl...
https://arxiv.org/abs/2504.21788
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Andrew Mann
9 months ago
New results from the Young Worlds Lab!
arxiv.org/abs/2504.13262
So you measured a stars' rotation period using a TESS light curve, how good is it? That's the question we wanted to answer with this paper. 🔭🧪⭐🌌
#exoplanets
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Quantifying the Limits of TESS Stellar Rotation Measurements with the K2-TESS Overlap
The Transiting Exoplanet Survey Satellite (TESS) has provided stellar rotation periods across much of the sky through high-precision light curves, but the reliability and completeness of these measure...
https://arxiv.org/abs/2504.13262
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ESO
9 months ago
1/ Using ALMA, in which ESO is a partner, the exoALMA project has revealed exquisite images of young solar systems. By studying the motion of the gas astronomers may find signs of planets in the making. Read more in this
@thenrao.bsky.social
release:
public.nrao.edu/news/exoalma/
🔭 🧪
#exoplanets
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