Measuring the Rotation Speed of Giant Stars from Gravitational Microlensing

Open Access
Publisher Website
Google Scholar
Abstract
During some gravitational lensing events, the lens transits the disk of the star. This event causes a shift in the apparent radial velocity of the star proportional to the star's rotation speed. The magnification of such an event is different from that expected for a point source. By measuring both effects, one can determine the rotation parameter v sin i. The method is especially useful for K-giant stars because these stars have turbulent velocities that are typically large compared with their rotation speed. By making a series of radial velocity measurements, one can typically determine v sin i to the same accuracy as the individual radial velocity measurements. There are approximately 10 microlensing transit events per year that would be suitable for these measurements.
All Related Versions

This publication has 14 references indexed in Scilit: