Probing Lensing Anomalies Network (PLANET) is an international collaboration of astronomers, with access to a variety of telescopes in the Southern Hemisphere, for detailed monitoring of microlensing. Whereas other projects, such as Optical Gravitational Lensing Experiment (OGLE), sample microlensing events (which typically last 15-90 days) every 10 to 100 days, PLANET is set up to collect data on a daily or hourly basis. One of the fruits of this approach was to observe atmospheric details in a giant K star in the galactic bulge that was the source of a microlensing event in 2000.¹

 

Reference

1. Albrow, M., et al. "Searching for Anomalies Through Precise, Rapid, Round-the-Clock Monitoring," Astrophysical Journal, 509, 687 (1998).