Our research interests can be categorized into Star Formation, The Young Sun and Early Planetary Evolution and Stellar Magnetic Activity:
We are studying issues of star formation, in particular effects of stellar radiation and particle flows onto the stellar environment such as protostellar disks and their physical and chemical development.
The Young Sun and Early Planetary Evolution
Our work on the “young Sun” and its planetary system has focused on the Sun’s short-wavelength output, especially in the context of its evolutionary history. Principal questions addressed by this work include:
- How does the output of a star like the Sun vary during its main-sequence evolution?
- How does enhanced short-wavelength radiation affect the planetary environments?
- Why was the output of the young Sun up to a thousand times stronger than at present?
- How are young stellar B fields structured?
- Stellar Magnetic Evolution and the “Sun in Time” Project
- Spectral Irradiance and Young Planetary Atmospheres
- The “Faint Young Sun Paradox” and the Young Radio Sun
- Magnetic Structure in the Young Sun
Stellar Magnetic Activity
We have worked in X-ray spectroscopy espeecially with XMM-Newton and Chandra to investigate magnetic structure of, and energy release in, stellar coronae and magnetospheres. Topics include:
- Composition of magnetized coronae;
- Physics of energy release during explosive flares; chromospheric evaporation physics;
- Long-term evolution of stellar atmospheres, and solar-stellar connection studies;
- Pre-main sequence high-energy evolution.
- The Inverse First Ionization Potential Effect
- Coronal Spectroscopic Diagnostics
- The Neupert Effect and Physics of Stellar Coronal Flares
- Statistical Heating and Numerical Simulations