M3, NGC 5272

A sixth magnitude globular cluster in the constellation Canes Venatici, this ball of 500,000 stars is approximately 160 light-years across and 100,000 light-years from Earth. This image of M3 is a combination of a B-band image and a Z-band image (Z is approximately from 8500 to 9500 A) taken on March 22, 2003, at the WIYN 3.5-meter telescope in 0.4 arc second seeing. The image was taken with the WIYN Tip-Tilt Module (WTTM), and will be used to study the variable stars in the cluster.