Τμήμα Φυσικής
ΣΧΟΛΗ ΘΕΤΙΚΩΝ ΕΠΙΣΤΗΜΩΝ ΕΚΠΑ
ΤΜΗΜΑ ΦΥΣΙΚΗΣ
ΤΟΜΕΑΣ ΑΣΤΡΟΦΥΣΙΚΗΣ ΑΣΤΡΟΝΟΜΙΑΣ ΚΑΙ ΜΗΧΑΝΙΚΗΣ
Σ Ε Μ Ι Ν Α Ρ Ι Ο
Τετάρτη 12 Δεκεμβρίου 2018, 13:00-14:00
Αίθουσα Διαλέξεων Τομέα Αστροφυσικής, Αστρονομίας και Μηχανικής
Δρ Σοφία-Παρασκευή Μόσχου
Center for Astrophysics | Harvard-Smithsonian
From Heliophysics to Extrasolar Space Weather and Habitability
The large number of verified exoplanetary discoveries has created the need for moving beyond the purely temperature-based definition of the “habitable zone” and account for stellar activity. The solar wind has been studied extensively for 60 years and is continuously monitored by a fleet of telescopes. Many temperate terrestrial exoplanets that have been found to orbit in close proximity to the most abundant stars, i.e. M-dwarf stars experience devastating stellar wind conditions. In addition to the stellar winds, in many cases the atmospheres of extrasolar planets face their host’s enhanced activity, which can have severe implications on their habitability assessment. While implications of UV and X-ray emission of superflares on exoplanets has started to be investigated, the effects of CMEs are purely theoretical due to lack of stellar CME observations. In the solar paradigm, energetic flares are associated with massive and fast CMEs. If the energy partition remains the same for the stellar regime, then we expect that monster CMEs will be a common phenomenon in active stars. Unlike stellar flares, direct imaging of stellar CMEs is beyond our current technological capabilities. Based on a number of indirect observational methods currently available, we present the most probable stellar CME candidates up to date. However, these methods have high uncertainty levels. Thus, computational methods need to be employed to examine the energy partition between flares and CMEs in Sun-like and more active stellar cases.