Globular cluster M92

The bright globular cluster Messier 92 (NGC 6341) in Hercules, from a B-band CCD image obtained with the prime-focus camera on the 4-meter telescope of Kitt Peak National Observatory. The cluster is off-center because this was a calibration exposure, centered on a group of well-measured standard stars on the cluster's southern outskirts. This image spans the full 14.3-arcminute field of the 2048x2048 CCD, block averaged by a factor of 4 in each dimension. A logarithmic intensity scale was used to simultaneously show bright and faint stars, windowed to conveniently disguise the fact that this four-minute exposure saturated the cluster core as well as a few of the brightest individual stars.

For more detail in the cluster core, distinguishing red giants from the brightest-main sequence stars, here is a 3-color composite image from the Jacobus Kapteyn Telescope (JKT) operated on the island of La Palma by the SARA consortium. The image quality ranges from 0.9-1.1 arcseconds between filters.

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Last changes: 5/2001      © 2001