Dartmouth Events

Abstract: This talk describes an ongoing project whose aim is to measure the spatial distribution and time evolution of small-scale magnetic starspots on a sample of stars with a range of masses and rotation rates.   In our technique, an apparent increase in brightness that appears as a 'bump' in the light curve during a planetary transit is the signature of a planet crossing in front of a spot that is cooler and darker than the surrounding photosphere.   The planet acts as a 'knife-edge' probe of the stellar surface highlighting brightness variations on the star and providing precise positional information about the spots in the path of the planet.    This modeling allows us  to explore the dynamo mechanism on stars other than the Sun and to understand how stellar properties influence the local magnetic field once it emerges on the surface.    We have used the star spot modeling program, STSP, to map the spatial distribution of spots on a variety of different stars including a slowly rotating K-dwarf, a rapidly rotating G-dwarf, a young rapidly rotating M-dwarf with a polar star spot, and an extremely slowly rotating red giant.  We will describe the technique, summarize the results of recent modeling, and discuss the future analyses that can be done with archived and newly derived  time series photometry of transiting planets.  

Hosted by Professor Elisabeth Newton