Lightnews — Scholar-powered news

Laura Kreidberg @lkreidberg.bsky.social · 23d

Incredible opportunity from the MPG to start your own research group!

Max-Planck-Gesellschaft @maxplanck.de · 23d

Early-career researchers: want to run your own lab? 🌟Max Planck Research Groups offer 6+ years, up to €2.7M in funding, open-topic freedom, team support & tenure-track opportunities. Intrigued? 😃Apply by Oct 14, 2025! www.mpg.de/max-planck-r...

Graphic with a blue background and light green dots. The text 'call for applications' appears in green, and 'Ausschreibung' in white. A white arrow on the right points diagonally upward.

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Laura Kreidberg @lkreidberg.bsky.social · 23d

APEx research focuses on exoplanet atmosphere characterization, from the ground and space. Small planets, big planets, transits, direct imaging, theoretical modeling (1D, 3D, interior), instrumentation (esp ground-based high-res) - we love it all!

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Laura Kreidberg @lkreidberg.bsky.social · 23d

We have job opportunities in the APEx department at MPIA - please spread the word!

Postdocs: aas.org/jobregister/...
Tenure-track staff: aas.org/jobregister/...
Max Planck Research Group Leaders: aas.org/jobregister/...

+ happy to host ERC, Humboldt, and other third-party funds.

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Reposted by Laura Kreidberg

Douglas Long @minimillian.bsky.social · Sep 4

The Rocky Worlds DDT has published our final target list. Join us for an information session on September 15 to learn more about the 9 targeted planets and the goals of the program.

🔭 #exoplanets

Rocky Worlds DDT Updates: Final Target List and Virtual Information Session

www.stsci.edu

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Laura Kreidberg @lkreidberg.bsky.social · Sep 3

My money is on bare rock for both planets - this simple explanation fits the data well, no fine-tuning needed. This may disappoint some folks, but I think it's amazing that we can measure this at all!! if atmospheres are rare on rocky planets orbiting M-dwarfs, that is a profound thing to know.

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Laura Kreidberg @lkreidberg.bsky.social · Sep 3

There *are* still some atmospheres that are compatible with the data, but the parameter space is shrinking - can't have too high surface pressure (> 1 bar) or too much CO2 (> 100 ppm or so). These scenarios are a bit finely tuned - a bare rock or thick, Venus-like atmosphere are easier to produce.

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Laura Kreidberg @lkreidberg.bsky.social · Sep 3

Now, we have a joint thermal phase curve for the planets, finding no significant heat redistribution from dayside to nightside. Here are the constraints on dayside and nightside temperature (K) for the planets. Dayside is red, nightside is blue, top row is planet b, and bottom row planet c.

Histograms of the dayside and nightside temperature constraints for TRAPPIST-1b and c. The nightside of both planets is consistent with zero, implying no evidence for heat redistribution by an atmosphere.

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Laura Kreidberg @lkreidberg.bsky.social · Sep 3

Previous measurements of thermal emission from planet b were consistent with either a bare rock or a thermal inversion in a CO2-rich atmosphere (arxiv.org/abs/2412.11627). Planet c was best fit by a moderately reflective surface or a thin atmosphere with not too much CO2.

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Laura Kreidberg @lkreidberg.bsky.social · Sep 3

Update on the atmosphere vs no atmosphere debate for TRAPPIST-1 b and c -- here's a nice and (IMO) conclusive result from Gillon and Ducrot et al.: no thick atmosphere on either planet. arxiv.org/pdf/2509.02128

arxiv.org

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Reposted by Laura Kreidberg

Max-Planck-Gesellschaft @maxplanck.de · Aug 1

Director at Max Planck - a unique position! The Open Call for Expressions of Interest in Max Planck Directorships is open now and can be submitted by the 31st of October 2025. ➡️ mpg.de/directors - Please share the Open Call among potential candidates.

Open Call for Expressions of Interest in Max Planck Directorships:
Expressions of interest can be submitted until 31 October 2025.

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Reposted by Laura Kreidberg

paulmolliere.bsky.social @paulmolliere.bsky.social · Jul 28

Our paper on PSO J318 is finally out 💪 . I want to thank all of my coauthors who made this study possible 🙇 !! It could be that we see the first cloud seeding nuclei forming at the top of the atmosphere…?

arxiv.org/abs/2507.18691

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Laura Kreidberg @lkreidberg.bsky.social · Jul 28

gorgeous new JWST spectrum of the rogue planet PSO J318 from @paulmolliere.bsky.social ! Strong absorption at 10 microns likely due to small SiO particles, acting as seeds for cloud formation arxiv.org/pdf/2507.18691

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Laura Kreidberg @lkreidberg.bsky.social · Jul 25

you did it!!!! 🙌

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Laura Kreidberg @lkreidberg.bsky.social · Jul 21

Compared to other planets in this temperature range, HD 86226c is surprisingly featureless ... indicative of either very high metallicity (which might have helped it survive in this intense irradiation environment), or high-altitude clouds. Or both!

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Laura Kreidberg @lkreidberg.bsky.social · Jul 21

Happy to share the first paper from the SPACE Program, led by my student Angelique Kahle! she observed a hot little sub-Neptune, HD 86226c (Rp = 2.3 Re; equilibrium temp = 1300 K). arxiv.org/pdf/2507.13439

The spectrum is *really* flat ! here's the amplitude compared to other gaseous planets.

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Laura Kreidberg @lkreidberg.bsky.social · Jul 14

@astroduncan.bsky.social did the impossible - he put magnetic fields in his models!! Check out this nice paper on how more realistic B fields impact hot Jupiter atmosphere circulation 🧲

Duncan Christie @astroduncan.bsky.social · Jul 14

My paper with Tom Evans-Soma and Nathan Mayne on magnetic drag models is now accepted and up on the arXiv. For a quick summary, look at the PDF of my Exoclimes poster that I shared last week.

www.arxiv.org/abs/2507.08511

Geometric Considerations in Hot Jupiter Magnetic Drag Models

Magnetic fields are expected to impact the atmospheric dynamics of hot and ultra-hot Jupiters due to their increased ionization fractions, compared to that of cooler exoplanets, but our ability to mod...

www.arxiv.org

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Laura Kreidberg @lkreidberg.bsky.social · Jul 3

Huge congratulations to @sophiavaughan.bsky.social for receiving the Michael Penston Prize from the RAS!!! Sophia is a pioneer in detecting reflected light from exoplanets. Congrats on this well-deserved recognition 😁🔭

Royal Astronomical Society @royalastrosoc.bsky.social · Jul 2

Time to hand out some prizes! 🏅🎉 🥳

The RAS is pleased to announce the winners of its prizes for the best PhD theses completed in the UK in 2024.

Dr Sophia Vaughan - Michael Penston Thesis Prize
Dr Graeme McGhee - Patricia Tomkins Thesis Prize
Dr Sihui Zhong - Keith Runcorn Thesis Prize

⤵️

From left to right, Dr Sophia Vaughan, Dr Sihui Zhong and Dr Graeme McGhee.

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Reposted by Laura Kreidberg

paulmolliere.bsky.social @paulmolliere.bsky.social · Jul 3

Hi exoplaneteers! Please consider submitting an abstract for the Observation and Characterization of Extrasolar Planets session of this year's meeting of the German astronomical society (deadline is 31 July, you first need to register).

ag2025.astronomische-gesellschaft.de/view_splinte...

Annual Meeting of the Astronomische Gesellschaft 2025

Annual Meeting of the Astronomische Gesellschaft 2025, held in Görlitz from September 15-19, 2025

ag2025.astronomische-gesellschaft.de

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Laura Kreidberg @lkreidberg.bsky.social · Jul 2

I had fun writing this with @stevensonanddone.bsky.social! thanks for being a great writing buddy!

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Laura Kreidberg @lkreidberg.bsky.social · Jul 2

Even though no atmospheres have been unequivocally detected, we're optimistic about the future! JWST's performance is excellent: with a larger sample of planets, more precise transmission spectra, and pushing to cooler targets, we are confident that atmospheres can be found (if they are there!).

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Laura Kreidberg @lkreidberg.bsky.social · Jul 2

The emission measurements are consistent with very hot daysides (ave. temp is 95% the maximum expected for a zero albedo bare rock). While some atmosphere scenarios are compatible with individual measurements, the ensemble of data is well fit by a simple picture where all the planets are bare rocks.

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Laura Kreidberg @lkreidberg.bsky.social · Jul 2

The transmission spectra are not (yet) precise enough to definitively detect molecules in many high MMW atmospheres. As a goal for future observations, we suggest a "five scale challenge" - reaching the precision needed to detect a CO2 feature in a nitrogen-rich atmosphere (like Earth's).

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Laura Kreidberg @lkreidberg.bsky.social · Jul 2

New paper out! This is a review of the published JWST observations of rocky exoplanets so far: arxiv.org/abs/2507.00933

Quick summary of the key points:

arxiv.org

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Reposted by Laura Kreidberg

Jiachen Liu @jiachenliu.bsky.social · Jul 1

My new paper, co-authored with Duncan Christie and Jun Yang, on 3D chemical kinetics simulations of K2-18b has been accepted by MNRAS!
This is Part I of a series. In Part I, we examine the planet's atmospheric dynamics and its impact on the transport of passive tracers.
arxiv.org/abs/2506.23891

Three-dimensional Transport-induced Chemistry on Temperate sub-Neptune K2-18b, Part I: the Effects of Atmospheric Dynamics

The low equilibrium temperatures of temperate sub-Neptunes lead to extremely long chemical timescales in their upper atmospheres, causing the abundances of chemical species to be strongly shaped by at...

arxiv.org

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Reposted by Laura Kreidberg

Tad Komacek @tadkomacek.bsky.social · Jul 1

I recommend giving this paper by @jiachenliu.bsky.social, @astroduncan.bsky.social, and Jun Yang a close read: arxiv.org/abs/2506.23891. Sub-Neptunes like K2-18b lie in an interesting regime where both the radiative feedback and mixing of chemical tracers is important, I’m looking forward to Part 2!

Three-dimensional Transport-induced Chemistry on Temperate sub-Neptune K2-18b, Part I: the Effects of Atmospheric Dynamics

The low equilibrium temperatures of temperate sub-Neptunes lead to extremely long chemical timescales in their upper atmospheres, causing the abundances of chemical species to be strongly shaped by at...

arxiv.org

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