Beautiful new direct imaging of the exoplanet Eps Ind Ab with the #JWST MIRI coronagraphs by Elisabeth Matthews of @mpi-astro.bsky.social et al - confirming previous detection of ammonia in its atmosphere, and suggesting the presence of water ice clouds. Great work! ๐ญ arxiv.org/abs/2603.08780
Are you a bachelor or master student anywhere in the world, and would like to come to us to work full-time on a supervised research project? Applications for the 2026 MPIA Summer Internship are open now!
The application for the ESO Summer Research Programme 2026 has just opened!
Itโs 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 โจ
๐ eso.org/sci/meetings...
The MPIA call for summer interns is now live! This is a great opportunity for bachelors & masters students from anywhere in the world to come an complete a three month, fully funded research project in beautiful Heidelberg. Check it out here: www.mpia.de/en/careers/i...
Congrats! I heard great things from a musician friend about this concert, too!
This paper from Currie et al has a version from a few years ago (fig. 1), but I think JWST has already changed the landscape quite a bit: ui.adsabs.harvard.edu/abs/2023ASPC...
I would also love an updated one if you track something down!
I heard 3000 ๐ซ
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
Our paper on PSO J318 is finally out ๐ช . I want to thank all of my coauthors who made this study possible ๐ !! It could be that we see the first cloud seeding nuclei forming at the top of the atmosphereโฆ?
arxiv.org/abs/2507.18691
Itโs a beautiful day in Cork to kick off our symposium on giant exoplanets and brown dwarfs #EAS2025
This image shows the exoplanet 14 Herculis c. The view is mostly black, with very faint red splotches in the central region of the image. At the center of the image, there is a black circle, and in the center of that, there is a star symbol representing a real star. This black circle blocks the light from the host star. To the lower right of the circle is a fuzzy bright orange circle, which is the exoplanet.
NEWS: #NASAWebb has directly imaged a cold exoplanet in an extremely misaligned orbit for the first time. The observations have surprised researchers in more than one way: webbtelescope.pub/3ZSctun #AAS246 ๐ญ ๐งช
Eventually yes, though I don't know the timeline
CORALIE has done most (all?) solar-like stars within 50pc, though most of the data isn't public
The evidence for biosignatures on K2-18b is flimsy, at best
Last week, Cambridge scientists announced the discovery of DMS and DMDS on K2-18b: what they call a "surefire biosignature."
Now, cut through the hype and get to the truth.
bigthink.com/starts-with-...
#space #astronomy #science
Artist's impression of the exoplanet K2-18b. Credit: A. Smith, University of Cambridge.
๐ก๐ผ, ๐ฎ ๐ฏ๐ถ๐ผ๐๐ถ๐ด๐ป๐ฎ๐๐๐ฟ๐ฒ ๐๐ฎ๐ ๐ป๐ผ๐ ๐ท๐๐๐ ๐ฑ๐ฒ๐๐ฒ๐ฐ๐๐ฒ๐ฑ ๐ถ๐ป ๐๐ฎ-๐ญ๐ด๐ฏ'๐ ๐ฎ๐๐บ๐ผ๐๐ฝ๐ต๐ฒ๐ฟ๐ฒ.
K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3ฯ'.
Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).
๐ญ๐งช๐ช #exoplanet
At some point we need to have a discussion about the ethics of participation in press releases as scientists. From todayโs K2-18b saga, Nikku Madhusudhan in the press release says โThe signal came through loud and clearโ (1/n)
An image with a black circle in the middle that represents the blocked out light of the central star, with a bright point source to the upper left of the star at about 1 arcsecond. To the right is another point source, a background star and a galaxy.
An image taken in polarized scattered light, showing the circumstellar disk around the star. The disk is face on and symmetric, apart from a wide faint gap in the upper left. The position of the gap is identical to the location of the candidate companion.
A direct imaging claim by Lagrange+ [https://arxiv.org/abs/2502.15081](โEvidence for a sub-jovian planet in the young TWA7 diskโ) - a very clear point source but only one epochโฆ but itโs in the gap in the disk around the star. Will be exciting to see follow up. ๐ญ๐ช #astrodon
Three panels showing the full measured spectrum, alongside a model. Most features in the measured spectrum are well explained with this model
I'll finish this thread with our full model of this atmosphere -- explaining (almost) every wiggle in the data. So much brown dwarf physics & chemistry is being unveiled with JWST!
An IFU image of a brown dwarf, alongside some plots of the noise terms present in this data.
In the appendices, we also get into the weeds of the data reduction, and appendix C discusses how we deal with one of the systematic effects present in out data. Might be of interest if you are also someone who worries a lot about the precise shape of your small wiggles in your JWST spectrum.
It's still unclear whether these molecules are common in cold brown dwarfs, since JWST has better resolution and sensitivity than any other instrument at 14um (where these molecules have features). We're working on more observations, though, so watch this space!!
Second, C2H2 (acetylene): this detection is really a puzzle. Models don't predict C2H2 in a non-irradiated atmosphere like this one, and we see quite a lot of it. We speculate about possible causes for this, but don't come to a clear conclusion. If you have any ideas, I'm all ears!
First, HCN (hydrogen cyanide): this is predicted for very turbulent atmospheres with very strong gravity: in these cases the HCN can be produced deep in the atmosphere, and brought up to observable altitudes.
A zoom-in of the spectrum between 13.4um and 14.6um. The plot shows models with and without HCN/C2H2, alongside the data, demonstrating that both molecules are confidently detected.
We modelled this spectrum using pRT retrievals (huge shout out to Paul Molliรจre for guiding me through this). We see H2O, NH3, CH4, as expected -- but also HCN and C2H2, which have not been seen in a brown dwarf atmosphere before. So, what do these molecules tell us about the atmospheric physics?
a spectrum of a cold brown dwarf, showing many molecular absorptions between 5 and 18um. Absorption features of H2O, CH4, NH3, HCN and C2H2 are marked.
We collected MIRI/MRS observations, which give a beautiful spectrum from 5-18um, all at R>1000. We see so much detail from all of the molecular absorption in the atmosphere -- all those wiggles you're seeing are real atmospheric structure!
In this study we used JWST to study a cold brown dwarf binary, WISE-0458, which is around 550 Kelvin / 280 Celsius. Even though it's a binary, here we treat it as a single atmosphere, since it is barely resolved even at the shorter wavelengths: we simply combine the signal from both brown dwarfs.
Delighted to share that my latest paper is finally out ๐ญ๐ช find it here arxiv.org/abs/2502.13610. This has been a real team effort -- huge thanks to my co-authors and the whole of the MIRI GTO team โจ
Nice writeup from @yollevoreloj.bsky.social of our recent paper, peering at a nearby exoplanet -- check it out!
www.nature.com/articles/d41...
With astronomy job season approaching, if youโre a PhD or early postdoc, PLEASE make a webpage and put your current contact details on it, so that searching for โ< your name > astronomerโ finds you first - more explanation how and why here: Unsolicited Advice #astrodon ๐ญ๐ช
just under 12 light years! This is one of the 20 closest star systems.
A team of researchers led by MPIA's @elisabethastro.bsky.social used JWST to image an old cold gas giant exoplanet. The measurement opens the door to studying cold Jupiter-like planets on wide orbits around old stars to test model ๐ญ
www.mpia.de/news/science...
