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Abstract:

There are about seventy-five billion terrestrial planets in our one Milky Way galaxy with temperatures capable of supporting surface life. They tend to orbit stars called K and M dwarfs, which are lower in mass and temperature than our Sun. The stellar ultraviolet (UV) radiation from these stars is strong and highly variable, and their planets are exposed to “superflares” daily in their first ~300 Myr. Knowing the UV environments of planets of all sizes is crucial to understand their atmospheric composition and evolution. For temperate terrestrial planets, characterization of the UV provides a key parameter in a planet’s potential to be habitable and helps us to discriminate between biological and abiotic sources for observed biosignatures, gases we hope will be signs of life. Shkolnik will present their efforts to study the UV exoplanet environments using existing space telescopes and describing new efforts to build dedicated UV space telescopes specifically designed to provide key information needed to answer these questions:

• How do planet atmospheres form and evolve under various stellar conditions?
• What are those planet atmospheres really made of and are they like those in our Solar System?
• Can planets around active stars be habitable and can we accurately interpret their biosignatures?

Speaker's Biography:

Evgenya Shkolnik is a professor of astrophysics at the School of Earth and Space Exploration at Arizona State University. She is an expert on exoplanets and stars, including the Sun. She studies stellar activity and star-planet interactions using telescopes on the ground and in space to answer questions involving stellar evolution and planetary habitability. Professor Shkolnik continues to execute new observations with existing telescopes both on the ground and in space. She is also now designing new small space telescopes dedicated to these experiments.

Professor Shkolnik's current research topics on Extrasolar Planetary Systems, Circumstellar Disks, CubeSat Astronomy include:

• Star-planet interactions as a probe of planetary and stellar magnetospheres.
• The search for and characterization of disks and planets around young M dwarfs.
• Identifying the young M dwarfs in the solar neighborhood for planet & disk searches.
• Gas emission from planetary atmospheres and debris disks.
• Effects of high-energy stellar radiation on the formation and evolution of planets.
• Evolution of planet habitability and necessary conditions for life.
• Building of CubeSat Telescopes