Great work everybody! 🙌

and Evie Ahrer @eahrer.bsky.social wrote a Nature comment on the JWST revolution for exoplanet atmospheres, from CO2 and photochemistry on gas giants to the push to smaller/cooler worlds www.nature.com/articles/s41...

Lorena Acuna @astrolore.bsky.social combined beautiful JWST spectra with mass and radius measurements for a warm Saturn, finding evidence for either a hot interior or a very small core - both unexpected! arxiv.org/abs/2511.13483

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!

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.

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.

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.

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.

you did it!!!! 🙌

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!