| Abstract : | The number of exoplanets that have been discovered has reached a staggering number of more than 5000. In this talk I will show the astonishing variety of exoplanets that have been discovered and the possibility of different kinds of atmospheres these planets can have. I will discuss how we study exoplanet atmospheres using the combination of observations from telescopes, planetary atmosphere models, retrieval techniques and thereby characterise them. I will show what we have discovered in various exoplanet atmospheres in the recent years using the Hubble Space Telescope (HST) and various ground-based surveys, along with the challenges that we encounter while characterising exoplanet atmospheres. James Webb Space Telescope (JWST) Transiting Exoplanet Early Release Science (ERS) program has given us unprecedented observations of various exoplanet atmospheres across multiple JWST instruments, with high precision and a large wavelength coverage spanning 0.5 to 5.6 microns. As a member of this JWST ERS team since its inception, I will present how these observations were planned, targets selected and their major goals. As part of the ERS program, transmission spectrum of WASP-39b, a hot Jupiter exoplanet was obtained using NIRCam, NIRSpec and NIRISS, 3 of the 4 instruments onboard JWST. I will show how we combined these observations with planetary atmosphere models to discover multiple gaseous species with very high confidence in the atmosphere of this planet. I will discuss the constraints on various chemical and physical properties as well as processes that we obtain. Finally, I will show where we are heading in our quest to demystify these far away worlds and in our search for habitable planets in our galaxy. |
