| Radio Observations of M Dwarf Magnetic Activity |
| Jackie Villadsen |
|
St. Mary's College of Maryland
USA |
| M dwarf planets experience the effects of the host stars' strong youthful magnetic activity for billions of years. Radio observations offer the possibility to detect extrasolar space weather events, including flares, stellar eruptions, and energetic particle events; however the ability to detect and characterize stellar space weather events in radio is at an exploratory stage. I will present a wideband radio survey of coherent (amplified) radio bursts on magnetically active M dwarfs. We searched for bursts that drift downwards in frequency over time, indicative of an outwards-moving shock caused by a coronal mass ejection. Instead we found that M dwarfs emit a population of coherent radio bursts, typically long-duration and strongly polarized, that originate in the stars' large-scale magnetic field, likely analogous to planetary and brown dwarf radio aurorae. These bursts extend to low frequencies, providing a foreground to radio space weather observations. Motivated by this finding, I will also present observations of coherent radio bursts on M dwarfs hosting close-in planets, where stellar radio bursts may be induced by star-planet magnetic interaction. |