Exoclimes_Conference_booklet1

Exoplanetary Extreme Space Weather
Ofer Cohen — Harvard-Smithsonian CfA!
Exoplanetary research is driven by the ultimate goal of defining whether life can exist
beyond the Earth and the solar system, while recent searches for exoplanets are focused
increasingly on detecting rocky, Earth-like planets around M-dwarf stars, which are by far
the most numerous type of star in the Universe. The “planet habitability” problem is a
cross-disciplinary topic where commonly, a planet is defined as habitable if its surface
temperature allows water to exist in a liquid form. However, there are other factors that can
impact planet habitability. M-dwarf stars are very active magnetically and their X-ray and
ultraviolet radiation in their habitable zones is much higher than we experience near the
Earth.
The physics of the solar atmosphere, the interplanetary environment, and the upper
atmospheres of planets in the solar system, including the Earth, is governed by the
radiation environment, electromagnetic forces, and the interaction between charged
particles and magnetic fields. In particular, the atmosphere of the Earth is shielded from
the intense radiation in space and from the solar wind by the Earth’s intrinsic magnetic
field. Here we present a set of numerical models, which were developed to study solar
system objects, and their application to exoplanetary, M-dwarf systems. These models
include detailed physical processes that are known to be important for solar system
bodies, but are commonly neglected in the context of exoplanets. Specifically, we
investigate the role of the planetary magnetic field in shielding the planetary atmosphere
from erosion by the extreme space environment in which it resides. Our study estimates
what planetary field strengths are necessary for protection from the caustic space
environment of M-dwarfs, and demonstrates how coronal mass ejections from M-dwarfs
affects the planet’s magnetospheres, and how much atmosphere is likely to be stripped
away in the larger events.
Defining Habitable Zones in Gravitationally Interacting Systems!
Siegfried Eggl — IMCCE Observatoire de Paris!
Calculating the extent of liquid-water habitable zones around main sequence stars
becomes challenging for systems with more than two gravitationally interacting bodies,
since the evolution of planetary orbits has to be taken into account. Given the recent
progress in determining liquid-water habitable zones within binary star systems we present
a generalized methodology to identify habitable-zone boundaries in multistar and
multiplanet systems.
Planning follow-up Space Missions searching for Atmospheric Spectral
Biosignatures from a sample of potentially habitable Earth-like Exoplanets!
John Lee Grenfell — Planetary Research Inst. DLR Berlin!
Next generation missions which aim at the atmospheric characterization of rocky
extrasolar planets could provide initial information on the amounts of carbon dioxide and
water molecules in the atmospheres of hot to temperate Super-Earths. Follow-up studies
may be needed however to search for (likely weaker) atmospheric biosignature signals
from a sample of Super-Earths. Until now, most studies have focused on the effects of
atmospheric carbon dioxide and water upon planetary climate, hence (potential)
habitability. There is, however, potentially additional information held in such data. On
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