Simulating Starspot Properties as a Function of Stellar Properties When Emergence Rates are High
Abstract
We wish to explore, under various stellar conditions, how aggregate starspot properties change when spot emergence rates are high. We use a Sun-based model to simulate the emergence, motion and decay of starspots on active stars. The spots are generated with a solar log-normal distribution of areas, and the emergence rate scaled according to the stellar rotation rate. The initial longitude of each spot is generated randomly, and initial latitude is generated with a normal distribution about a changing average, equivalent to the solar butterfly diagram. The spots are then allowed to decay at a rate dependent on the stars' surface turbulence, with a motion determined by the differential rotation and meridional flow. At high emergence rates spots can erupt into old ones, where we will either experience a merger or (partial) destruction, depending on their polarity. We follow this evolution over a magnetic cycle, logging the resulting distribution of spot sizes, latitudes, decay rates and destruction (flare) rates, for varying input parameters and stellar conditions. We compare our results with both stellar observations (including light curves, apparent spot distributions, measured differential rotation and flare rates) and theoretical estimates such as magnetic diffusivities.
- Publication:
-
American Astronomical Society Meeting Abstracts #227
- Pub Date:
- January 2016
- Bibcode:
- 2016AAS...22714513H