ELASSS July 2023 - Caprice Phillips, The Ohio State University (US)

TITLE:  Exploring Potential Biosignatures in Exoplanet Atmospheres with Current and Future Telescopes

SPEAKER: Caprice Phillips, The Ohio State University (US)

WHERE: JCMB 5326

WHEN: July 4, 3.00pm

The seminar will also be available online, recorded and it will be available upon request.

Abstract: Exoplanets with radii between those of Earth and Neptune (1.7 - 3.4 Earth radii) have stronger surface gravity than Earth and can retain a sizable hydrogen-dominated atmosphere. In contrast  to gas  giant planets, we call these planets gas dwarf planets. Furthermore,  terrestrial planets below the radius valley (< 1.5 Earth radii),  may also have the ability to hold onto hydrogen-dominated atmospheres. Generally, planets with hydrogen/helium dominated atmospheres may be more amenable targets for transmission spectroscopy with current and upcoming space-based missions. In this talk, I will discuss the investigation of the detectability of ammonia (NH3, a potential biosignature) in the atmospheres of hydrogen-dominated exoplanets with JWST and Twinkle. I will present results from recent work on simulating ammonia detectability on temperate gas dwarfs and terrestrial planets with JWST and Twinkle. I will demonstrate how varying atmospheric scenarios and conditions (e.g. cloud conditions, mean molecular weight, and NH3 mixing ratios) affect the ammonia detectability. Finally, I will show the potential of Twinkle to characterize the atmosphere of potentially habitable exoplanets.