Starburst
For my thesis project, I am working on the Starburst program (follow the link for a more detailed description of my work). The Starburst program will be a 2-year-long nightly observing program dedicated to dynamic radio spectroscopy of coherent stellar bursts, recording spectra with ultra-wide bandwidth and fast cadence. I will use the Starburst program’s dynamic spectra of stellar radio bursts, along with VLA and VLBA observations, to constrain properties of CMEs around active stars: rate, velocity, mass, dependence of direction on star's magnetic field configuration - properties needed to assess the role of coronal mass ejections in space weather around active stars (stellar mass loss and angular momentum loss, planetary habitability).
.
An erupting solar prominence observed by the SOHO mission is part of a coronal mass ejection. Image credit: ESA/NASA.
The figure on the left below is a dynamic spectrum tracing the evolution of the frequency spectrum of a solar radio burst over time. The burst shown below is produced at the shock front of a coronal mass ejection as it moves outwards through the corona (illustrated in the diagram on the right). The Starburst program will search for similar bursts on nearby active stars.
Left: Dynamic spectrum of a long-duration solar radio burst associated with the shock front of a coronal mass ejection (Green Bank Solar Radio Burst Spectrometer/Stephen White). The shock front of a coronal mass ejection accelerates electrons, resulting in emission at the fundamental plasma frequency and the lowest harmonic. Right: As the CME moves outwards, it moves into lower densities and thus the radio emission sweeps to lower frequencies. The frequency structure of the burst can be used to measure the radial velocity of the CME.