Speaker
Description
Most stars are M dwarfs, many of which possess kilogauss magnetic fields. For the subset of those with fields arranged into strongly dipolar magnetospheres, the simplest application of the Hillas criterion suggests that these magnetospheres could trap protons with energies up to 20 PeV, and a more cautious estimate puts the limit at tens of TeV. This presentation explores the prospects for M dwarfs as sources of TeV particles. I assess whether particle acceleration processes previously discussed for other objects with dipolar magnetospheres—from planets to pulsars-–should be considered for M dwarfs. I also present preliminary results from a search for gamma ray emission with Fermi data for the nearby M dwarf UV Ceti. Previous searches for gamma ray emission from M dwarfs have not considered the importance of focusing on those with dipolar magnetospheres. Radio emission from UV Ceti includes auroral activity, indicative of particle acceleration in large-scale current systems in the dipolar magnetosphere, and I include recent observations of this star with the Very Large Array.
