JWST Reconnaissance Transmission Spectroscopy of the Earth-Sized Exoplanets TRAPPIST-1 b and g

Olivia Lim ( Université de Montréal )

One of the greatest and most intriguing unanswered questions in the field of exoplanets is whether Earth-like planets outside our solar system have atmospheres suitable for the emergence of life. Ever since its discovery, the TRAPPIST-1 system has given us hope and has fueled us with excitement to finally answer this long-standing question. Located in the solar neighborhood at only 12 parsecs and with its seven Earth-sized rocky planets, three of which being in the habitable zone of the system, TRAPPIST-1 may be our best shot at detecting and potentially characterizing atmospheres on small temperate exoplanets. All these planets periodically transit their Jupiter-sized M8V-type host star, allowing us to probe their atmosphere via transmission spectroscopy. Each TRAPPIST-1 planet has previously been observed in transit with the Hubble Space Telescope and cloud-free, hydrogen-rich atmospheres were confidently rejected on all seven of them. However, thinner atmospheres, such as the one we have on Earth, require a much better precision to be detected or ruled out. In this talk, we will present the first high-precision transmission spectra of TRAPPIST-1 b and g based on transit observations using the Near-InfraRed Imager and Slitless Spectrograph (NIRISS) and the Near-InfraRed Spectrograph (NIRSpec) aboard JWST. The quality of this data set provides a foretaste of some of the most exciting science that the JWST era will enable, namely in the field of Earth-sized exoplanets in the temperate regime.