iiinova — where your digital self keeps evolving

Bibiana Prinoth @handle.invalid · 15/09/2026

Last but not least: Please help spread the word. I feel like many people missed this because the word population sounds scary. But we are there, we are studying planets beyond isolated objects. Be part of this family, and help us push the next decades of exoplanets science @eso.org!

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Bibiana Prinoth @handle.invalid · 15/09/2026

Does this all sound interesting to you? Then check out our webpage here: www.eso.org/sci/meetings... Registration deadline is on September 20! Be quick, hope to chat with you about #exoplanets there!! 🪐

eso.org

ESO - Bridging Horizons

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.

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Bibiana Prinoth @handle.invalid · 15/09/2026

... paving the way for discoveries that the ELT will later explore in greater depth! So now is the time to get together, talk strategy, talk POPULATIONS, and even start dreaming of what we need beyond the ELT (Expanding Horizons!).

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Bibiana Prinoth @handle.invalid · 15/09/2026

... but their discoveries will rely critically on synergies with ground-based observatories! ESO’s current facilities, VLT, VLTI, and ALMA offer complementary strengths in demographics, atmospheric characterisation, planet formation, and system architectures, ...

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Bibiana Prinoth @handle.invalid · 15/09/2026

Our push: Exoplanet science is entering a transformative decade. The upcoming ESA missions PLATO (~2026) and Ariel (~2029) will revolutionise the detection of Earth analogues and the study of planetary atmospheres through large-scale surveys, ...

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Bibiana Prinoth @handle.invalid · 15/09/2026

If you are a bit like me, you may have found yourself asking: What do we learn from exoplanet X alone? Maybe we should start putting it in context with the population. This is EXACTLY what we are aiming at with this workshop. In short: Exoplanets can nowadays be studied as a population!

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Bibiana Prinoth @handle.invalid · 15/09/2026

In case you have missed it, we are hosting a super cool workshop on #exoplanets studies in Garching, Vitacura and Nice (YES, 3 places at the same time!!!) in November. Bridging Horizons: Harnessing ESO's current facilities for the dawn of exoplanet population studies Dates: **2-6 November 2026**

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BOWIE+ Seminar Series @bowieseminar.bsky.social · 01/09/2026

Cathal Maguire's talk on limb asymmetries in exoplanet atmospheres is now available, just in time to inspire your JWST proposal writing. #exoplanets #astronomy www.youtube.com/watch?v=f47c...

youtube.com

Limb from Limb: Observing Atmospheric Asymmetries from the Ground and Space - Cathal Maguire

YouTube video by BOWIE+ Seminars

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Linn Boldt-Christmas @nplinnspace.bsky.social · 10/08/2026

…and here, ”recently” = ”within 1 million years” 😅 but that’s like, *SO* recent in planet terms!! ”…models [showed] liquid can be transported […] through small conduits, similar to lava or geyser tubes, driven by buoyancy or pressure from below.” Such neat combo of several cool physics topics! 🔭🧪🪐🌋

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Bibiana Prinoth @handle.invalid · 26/07/2026

Gonna do something a bit scary on Monday 🙃 I‘ll be talking about magnetic fields on #exoplanets in German 🥺

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Forming Worlds Lab @formingworlds.space · 23/07/2026

New paper led by Joe Williams (@exeter.ac.uk), with our group among the co-authors ❄️ "Planetesimal Formation Across the Stellar Mass Spectrum and its Influence on Exoplanet-Inherited Volatile Budgets" Read the paper: arxiv.org/abs/2607.20271 #Exoplanets #PlanetaryScience

Two-panel schematic comparing how a protoplanetary disc evolves around a very low mass star and around a heavier one. The top panel, labelled 0.1 solar masses, follows a disc fed briefly by material falling in from the collapsing cloud: the disc expands, dust coagulates into icy pebbles, the pebbles drift inward and deliver their ice to the water snowline where a single generation of planetesimals forms, and the dust is then depleted, leaving grey dehydrated planetesimals. The bottom panel, labelled 0.3 solar masses and above, shows the same sequence but with a first generation of planetesimals already forming during the infall phase and a second generation later at the snowline, leaving a mix of blue water-rich and grey dehydrated bodies. A colour key marks rocky pebbles, the water sublimation front, water ice, dehydrated planetesimals and water-rich planetesimals, and an arrow along the bottom marks time running left to right.

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ESO @eso.org · 22/07/2026

That's no moon. It's a...hang on, what should we call it? 🤔 Our VLT has revealed evidence for a moon-like object in the CD-35 2722 system. Yet this new ‘exomoon’ detection is challenging cosmic labels! 🔭 🧪 #exoplanets 1/4

The artist's impression features a small star (left) and two gaseous bodies (centre and right), set against the blackness of space. Credit: ESO/M. Kornmesser.

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ESO @eso.org · 15/07/2026

Ten years of hide-and-seek! 🫣 Astronomers used our VLT to find a new #exoplanet orbiting the famous star Beta Pictoris — hiding in archival ESO observations spanning over a decade! And it's shyer than any exoplanet we've imaged before. 🔭 🧪 1/3 📷 ESO/B. Sutlieff, M. Bonse et al.

Image of a star system. The central star is hidden behind a coronagraph, marked by a white star symbol at the centre. A bright companion appears to the left, while a much fainter companion, indicated by a white arrow, is visible to the right against a reddish-orange background.

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Sarah Kendrew @sarahkendrew.bsky.social · 14/07/2026

A major take-home from #SPIEAstro is that the level of scientific ambition in the European ground-based astronomy community is sky-high following the successes of VLT/VLTI, ALMA and the progress on ELT. @eso.org is *the* global leader in this area. This event sounds fab.

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Bibiana Prinoth @handle.invalid · 14/07/2026

The good news is that the ship hasn’t sailed yet! The process is only getting started! If you’ve been thinking about getting involved, this is your sign 😊 I’d love to see more early-career researchers help shape the facilities many of us will spend our careers using. next.eso.org/timeline/ 3/3

next.eso.org

Timeline

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Bibiana Prinoth @handle.invalid · 14/07/2026

That surprised me, because many of us will (hopefully!) be the generation that gets to use these facilities. If I’m lucky, I’ll be retired in about 40 years 😄 So I’m curious: what kept „us“ from submitting? Lack of awareness, time, confidence, opportunities, mentorship, or something else? 2/3

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Bibiana Prinoth @handle.invalid · 14/07/2026

Hi #exoplanets folks, I’m attending the Expanding Horizons conference @eso.org this week (thinking about the facility post-ELT… terrifying, I know 😅). One thing that came up is that relatively few early-career astronomers submitted (co-authored) white papers for the process. next.eso.org 1/3

next.eso.org

Expanding Horizons

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Linn Boldt-Christmas @nplinnspace.bsky.social · 06/07/2026

A very merry yee-haw to all horse girls & cowboys (gender neutral: horse cows?) attending #HoRS3S in Granada this week! I've sadly ended up unable to attend IRL this year, but am sending my best in the form of a poster that'll be up in my absence on #exoplanet WASP-107 b 🔭🤠💖🐎🧪 Have a fun week y'all!

Don’t throw away your rubbish ground-based transit data (yet)! -- A cautionary tale starring warm super-puff WASP-107 b and VLT

The problem: Ground-based transmission spectroscopy observations have seen remarkable success in characterising hot Jupiter exoplanets in the last decade with increasingly high detail, and our hope is to eventually characterise smaller, cooler exoplanets similarly – one day, even Earth-like targets. To get there, we have to explore what shortcomings exist in our current observational capabilities and methodology by exploring an ”in-between” target: the neither-temperate-nor-hot Neptune-sized WASP 107-b (Teq ≈ 740K).

Method: WASP-107 b is already well-studied from space, and thus a good playground for assessing the quality of our ground-based approaches. It is observationally favourable in some ways (e.g. good scale height) but more challenging in others (e.g. cloudy, cooler Teq), making it a good case study for our tried-and-tested techniques like cross-correlation. A number of molecular species had already been detected by JWST, but could we do it from the ground? By using a combination of real and simulated data, we could explore what aspects of traditional methods perform well for these challenging targets, and which need a rethink.

We found that for cooler and cloudier targets like WASP-107 b, the amount of signal that one can reasonably expect is unfortunately very low. Several factors can compound and effectively create scenarios where there is simply not enough signal to reach detections of S/N ≥ 5, even if everything is done ”correctly”. What looks like bad data might not be bad, just… as good as we can get, for now!

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Andrew Mann @amann.bsky.social · 02/07/2026

Last is the SOYSAUCE survey, PI Madyson Barber. Work on studying the alignment between planets and their host stars, focusing on <200 Myr systems (fast misalignment or primordial misalignments). So far, things look aligned. This was done as a twilight zone reference 🧪🔭⭐ #exoplanets

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Bibiana Prinoth @handle.invalid · 03/07/2026

Very excited to hear about this next week at HoRS3S!

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Bibiana Prinoth @handle.invalid · 30/06/2026

I am giving a keynote at the HoRS3S conference next week (my first keynote so consider me very excited 🥹) & seriously it‘s so much fun prepping those slides 🤭 Shoot me a message if you‘re coming to HoRS3S next week. I might find a way to give you a shoutout 😋 #exoplanets

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Bibiana Prinoth @handle.invalid · 29/06/2026

Anyone doing some live-posting from #Exo6 #Exoplanets6? Not seeing anything on #exoplanets but maybe I am blind? FOMO is kicking in (but I really needed the break 😬)

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Bibiana Prinoth @handle.invalid · 28/06/2026

unfortunately this time without me 😬

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Duncan Christie @astroduncan.bsky.social · 23/06/2026

MPIA PhD student Angelique Kahle has a very cool paper out today looking at everyone's favourite ultra-hot Jupiter, WASP-121b. Angelique is giving a talk on the results next Monday at Exoplanets VI, as well. #exoplanets arxiv.org/abs/2606.21855

arxiv.org

The panchromatic JWST dayside spectrum of WASP-121 b reveals a refractory-rich formation

One path to understand how planets form is to link their present-day atmospheric composition to predictions from planet formation models. For the hottest planets, the abundances of refractory species ...

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Bibiana Prinoth @handle.invalid · 28/06/2026

It’s also an ingredient for toothpaste and sunscreen. I have been invited to so many medical conferences since I published about TiO, it’s kinda hilarious 🤭

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Bibiana Prinoth @handle.invalid · 26/06/2026

However, in all fairness: Whether the depletion is universal or itself temperature dependent remains an open question. I'm really excited to see more population-level studies, seeing them become a trend of their own - and I think they have huge potential. Hopefully, this is just the start! 21/21

arxiv.org

A population view of transiting hot giant exoplanets: Tracing Fe and Ti chemistry with ESPRESSO and MAROON-X

Hot and ultra-hot Jupiters offer a unique laboratory to study atmospheric chemistry at the population level using ground-based high-resolution spectroscopy. Fe and Ti are key tracers of thermal and ch...

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Bibiana Prinoth @handle.invalid · 26/06/2026

tldr: In this paper, we combine a large observational data set, introduce a population metric, and show that the observed Ti/Fe trend can be explained either by temperature-dependent depletion or by temperature inversions triggering condensation. 20/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

My dream is to study these planets from both perspectives simultaneously and finally show that titanium really is less abundant than equilibrium chemistry predicts... ...because it's literally raining titanium compounds. ☔️ 19/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

However, big caveats: a) We're comparing forward models to the data, not performing full atmospheric retrievals. Someone, pls? b)Transmission spectra don't strongly constrain the T-p profile. What we really need are systems simultaneously studied in both transmission and emission. 18/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

... the hottest planets still seem globally depleted in titanium relative to iron! Those inversion models reproduce the observed population trend surprisingly well, but there is no need to invoke increasingly stronger depletion toward cooler planets. See for yourself! 17/n

model comparison for isothermal (left) and gradient (right) models. Isothermal models need a temperature dependent depletion, while gradient models do not!

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Bibiana Prinoth @handle.invalid · 26/06/2026

But here's my favourite part in our model comparison: When we introduce temperature inversions, Ti-bearing species naturally disappear from the observable atmosphere because they condense efficiently in the deeper layers. Yet ... 16/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

The hottest planet in our sample (WASP-189 b) is much closer to only a 10x titanium depletion. (Still depleted, but much less.) Fun bonus: the day after this paper appeared on arXiv, Stefan Pelletier uploaded his, finding this ~10x Ti/Fe depletion for WASP-189 b! 🔗 arxiv.org/abs/2606.15934 15/n

arxiv.org

The breaking of cold traps and onset of titanium in ultra-hot Jupiter atmospheres: WASP-189b in context

Condensates are ubiquitous to all Solar System planets with significant ($>$10mbar) atmospheres. The same is true for most exoplanets with characterised atmospheres, with even ultra-hot exoplanets bei...

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Bibiana Prinoth @handle.invalid · 26/06/2026

With isothermal atmospheres, reproducing the observations requires removing increasingly more titanium relative to iron as planets get cooler (temperature-dependent coldtrap) The coolest planets require titanium abundances about 100x below stellar values, while iron can remain near stellar. 14/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

But can we reproduce this trend with models, you ask? We did too. We performed a large suite of model injections. We used simple isothermal atmosphere models, and models containing temperature inversions that make the deeper atmosphere cold enough for TiO to condense (we call them gradient). 13/n

temperature pressure profiles and cross-correlation contribution functions.

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Bibiana Prinoth @handle.invalid · 26/06/2026

So instead of comparing the cross-correlation signals of Fe and Ti planet by planet, we defined a relative metric (details are in the paper if you care) that lets us place them on the same figure. And it's clear: Ti weakens much faster than Fe toward cooler planets. 🔗 arxiv.org/abs/2606.14490 12/n

metric against equilibrium temperature showing a downwards trend with decreasing temperature. Titanium disappears "faster"/ "more" than iron!

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Bibiana Prinoth @handle.invalid · 26/06/2026

Iron is almost ubiquitous in these atmospheres. Titanium, on the other hand, seems much more sensitive to temperature - even differences of only a few hundred Kelvin appear to matter if we are able to detect it or not. 11/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

Suddenly, my abandoned population-study idea was back on the table, and we analysed 15 hot and ultra-hot gas giants observed with ESPRESSO on the VLT and MAROON-X on Gemini North. @eso.org @noirlabastro.bsky.social The goal: compare iron and titanium across the entire population. 10/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

That discovery sparked a new question: how does titanium behave across the whole population of hot and ultra-hot Jupiters? And how does it compare to iron? Fortunately, I knew exactly the right people at exactly the right time, because they had just observed the missing part of the population! 8/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

But turns out, we just needed to point the mini-ELT at it, and it popped out super shiny ✨ So with a much larger "telescope", we could still detect titanium! It was depleted compared to equilibrium predictions (and compared to elements like vanadium), but it was definitely there! 7/n

This image shows the clear titanium atmospheric trace of WASP-121 b.

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Bibiana Prinoth @handle.invalid · 26/06/2026

This resulted in a paper where we detected titanium in a planet - WASP-121 b - where we thought it would be absent (and previous observations supported that) because efficient cold trapping should have removed it from the observable atmosphere. 🔗 www.aanda.org/articles/aa/... 6/n

aanda.org

Titanium chemistry of WASP-121 b with ESPRESSO in 4-UT mode | Astronomy & Astrophysics (A&A)

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

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Bibiana Prinoth @handle.invalid · 26/06/2026

Fast forward a few years. I had just returned from an incredible year in Chile, working with ESPRESSO observations taken using all four Unit Telescopes of @eso.org's VLT - effectively giving us the collecting area of a 16 m telescope. I love to call this mode the "mini-ELT" mode! 5/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

That "side project" sat untouched while my first paper turned into three papers on the same planet WASP-189 b. That planet kept me busy for quite a while, you could say (well, the majority of my PhD to be honest 😬) 🔗 www.aanda.org/articles/aa/... 🔗 www.aanda.org/articles/aa/... 4/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

I even created an Overleaf project titled "The Onset of Iron Absorption" and started collecting every suitable observation I could find, no matter the spectrograph. Maybe unsurprisingly, the project was quickly overshadowed by shiny new data, and somehow ended up in the back of my mind 🙈✨ 3/n

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Bibiana Prinoth @handle.invalid · 26/06/2026

But let's start from the beginning... After publishing my very first PhD paper, I became intrigued by one question: instead of studying iron in a single ultra-hot atmosphere, why not across the entire observed population? 🤔 I set out to do that ... 🔗 www.nature.com/articles/s41... 2/n

nature.com

Titanium oxide and chemical inhomogeneity in the atmosphere of the exoplanet WASP-189 b - Nature Astronomy

The rich transmission spectrum of exoplanet WASP-189 b reveals its dynamical atmosphere with a three-dimensional thermochemical stratification, requiring the unification of dynamical, thermal and chem...

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Bibiana Prinoth @handle.invalid · 26/06/2026

Last week, I uploaded my first first-author paper as Dr. Prinoth to arXiv, and I finally have time to tell you about it. This one has been a long time coming, and I'm incredibly happy and proud that it's finally out in the #exoplanets world! 🔗 arxiv.org/abs/2606.14490 1/n

arxiv.org

A population view of transiting hot giant exoplanets: Tracing Fe and Ti chemistry with ESPRESSO and MAROON-X

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Bibiana Prinoth @handle.invalid · 25/06/2026

Thank you for all your support ever since I stepped into this field, Jayne! You are a true role model ❤️

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