Free Astronomy Magazine November-December 2026

30 NOVEMBER-DECEMBER 2026 ASTRO PUBLISHING https://www.youtube.com/watch?v=cS9uYH837Cc&t=12s T his Space Sparks episode high- lights one of Webb’s largest im- ages to date that showcases the hunt for the smallest brown dwarfs. [ESA/Webb, NASA, CSA, JPL-Caltech, DSS2, K. Luhman, C. Alves De Oliveira, N. Bartmann (ESA/Webb), A. Kamkar, L. Cieza, E. Slawik, N. Risinger, M. Zamani (ESA/Webb)] IC 348 in 2022, when they discovered brown dwarfs with masses as low as three to four times the mass of Jupiter. Now, the same research team has used Webb to probe even deeper into this region in search of even smaller brown dwarfs. The team used Webb’s NIRCam (Near-Infrared Camera) in 2024 to capture the warm glow of young brown dwarfs and newborn stars that we see in this new image of IC 348. After selecting candidate brown dwarfs based on their colours and brightness, they fol- lowed up with Webb’s NIRSpec (Near-Infrared Spectrograph) in 2025 to conduct spectroscopic observa- tions to study the masses of the brown dwarfs. These deep Webb ob- servations revealed something re- markable: brown dwarfs with masses as low as just twice the mass of Jupiter — just 0.19% of the Sun’s mass. These are the least massive brown dwarfs known, and their exis- tence poses a challenge to models of pheres of the lowest-mass brown dwarfs, suggesting that these ex- treme objects might exist in a spec- tral class of their own. The stars and brown dwarfs of IC 348 aren’t the only attractions in this photo. A brilliantly detailed collec- tion of protostars occupies the upper-right corner of the image. Sev- eral of these protostars are accompa- nied by Herbig-Haro objects, which are luminous regions that form when jets from growing newborn stars crash into the gas and dust around the star. The long, narrow object that is ori- ented horizontally in this corner is HH 797, which was featured previ- ously as a Webb Picture of the Month. Upon close inspection, this source is revealed to be two proto- stars with nearly parallel outflows. Just to the right of HH 797 is the pro- peller-shaped source HH 211, which features both narrow jets and broader outflows. how stars form. In addition to the discovery of these unexpectedly lightweight brown dwarfs, the Webb observations contained even more surprises. One of the lightest newfound brown dwarfs showed signs of a disc, suggesting that plan- ets could be forming around it de- spite the brown dwarf being the mass of a planet itself. While inspecting the spectra of IC 348’s brown dwarfs, the research team also found a feature that they attributed to hydrocarbons, which are molecules made only of hydro- gen and carbon atoms. This feature has only been seen in the atmos- !