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The abundances of main carbon- and oxygen-bearing gases in the atmospheres of giant exoplanets provide insights into atmospheric chemistry and planet formation processes 1,2 . Thermochemistry suggests that methane (CH 4 ) should be the dominant carbon-bearing species below about 1,000 K over a range of plausible atmospheric compositions 3 ; this is the case for the solar system planets 4 and has been confirmed in the atmospheres of brown dwarfs and self-luminous, directly imaged exoplanets 5 . However, CH 4 has not yet been definitively detected with space-based spectroscopy in the atmosphere of a transiting exoplanet 6-11 , but a few detections have been made with ground-based, high-resolution transit spectroscopy 12,13 including a tentative detection for WASP-80b (ref. 14 ). Here we report transmission and emission spectra spanning 2.4-4.0 μm of the 825 K warm Jupiter WASP-80b taken with the NIRCam instrument of the JWST, both of which show strong evidence of CH 4 at greater than 6σ significance. The derived CH 4 abundances from both viewing geometries are consistent with each other and with solar to sub-solar C/O and around five times solar metallicity, which is consistent with theoretical predictions 15-17 ., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Hubble Space Telescope (HST) at 1.6 µm. We find that unresolved nuclear emission from nine of 14 nuclei varies at the level of 10%-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are nonstellar and associated with the central parsecs of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys; however, high angular resolution infrared observations will provide a way to measure time delays in these galaxies.