TRAPPIST-1 Revisited, Again

Yeah, so the first JWST spectrum for TRAPPIST-1e just dropped! I can’t wait to see the analysis and find out what atmosphere it has and -

And -

Oh. Never mind.

For anyone wondering, the spectrum looks like this:

TRAPPIST-1e spectrum.
NASA, ESA, CSA, STScI, J. Olmsted (STScI) (CC BY 4.0)

As you'll notice, the error bars are pretty big. There's some wiggles there that might be signs of an atmosphere, which is promising, but because there's so much error we can't exclude the scenario where the planet is just a bare rock¹. Unfortunately it seems like the star TRAPPIST-1 contaminated the spectra and we're not sure whether the wiggles are coming from that or from a genuine atmosphere¹. There's already a followup study in the works which will use the likely airless TRAPPIST-1b as a baseline to correct out any star-induced wiggling¹, which is pretty clever, but it'll take some time for those data to be collected and interpreted. In the meantime, we'll just have to wait.

References

¹ Glidden, A., Ranjan, S., Seager, S., Espinoza, N., MacDonald, R. J., Allen, N. H., Cañas, C. I., Grant, D., Gressier, A., Stevenson, K. B., Batalha, N. E., Lewis, N. K., Long, D., Wakeford, H. R., Alderson, L., Challener, R. C., Colón, K., Huang, J., Lin, Z., Louie, D. R., ..., & van der Marel, R. P. (2025). JWST-TST DREAMS: Secondary atmosphere constraints for the habitable zone planet TRAPPIST-1 e. The Astrophysical Journal Letters, 990(2), L53. https://doi.org/10.3847/2041-8213/adf62e