Instrumentation Commons^™

Counting Photons To Calibrate A Photometer For Stellar Intensity Interferometry, Jason Chew

Physics

We use a telescope and photometer to observe stellar photons and measure the rate of observed photons. Based on intensity spectra from the Spectrophotometric Catalogue of Stars, we also predict expected values for the photon rates, which we compare to our measurements. From this comparison, we measure the local optical depth to be τ = 0.60±0.25, a reasonable value. We find that our predictions are directly proportional to our measurements by a factor of 0.98 (+0.02, -0.27) . The similarity between our measurements and expectations shows that we are able to both predict and measure photon rates with accuracy.