Variable stars are stars whose brightness fluctuates over time. Mike Simonsen, a variable star observer, was interviewed on the radio show The Event Horizon to discuss his work observing and monitoring the brightness of variable stars. He explained how amateur astronomers can identify and track variable stars to help professional astronomers study stellar phenomena like pulsations and eclipses that cause stars to periodically brighten and dim.

1. Slooh Radio June 20, 2008 The Event Horizon with Special Guest Mike Simonsen on Variable Star Observing