Using intensity interferometry to double-check the size of Red Clump stars

Star system: HD 17652 | Distance from the Sun: 177 light years

Scientists are testing a specialized method called intensity interferometry to measure the precise physical dimensions of 'Red Clump' stars, such as HD 17652. These aging stars are vital benchmarks used to calculate distances across the universe, including the gap between us and the Large Magellanic Cloud. 

By analyzing how light interferes at different wavelengths, researchers can map the stellar surface and account for 'limb darkening'—the effect where a star appears dimmer toward its edges. This new approach provides a crucial independent check on existing data, ensuring our cosmic distance scales are accurate to within 1%.

Scientific study

Validating the Angular Sizes of Red Clump Stars with Intensity Interferometry (external link)