The Canada-France-Hawaii Telescope ( CFHT ) Adaptive Optics Bonnette ( AOB ) has been used to obtain high angular resolution JHK images of the centers of the metal-poor globular clusters NGC5272 ( M3 ) , NGC6205 ( M13 ) , NGC6287 , and NGC6341 ( M92 ) .
The color-magnitude diagrams ( CMDs ) derived from these data include the upper main sequence and most of the red giant branch ( RGB ) , and the cluster sequences agree with published photometric measurements of bright stars in these clusters .
The photometric accuracy is limited by PSF variations , which introduce systematic errors of a few hundredths of a magnitude near the reference star .
The NGC6287 CMDs are of particular interest , as they are free of the scatter caused by foreground stars and differential reddening that have plagued previous efforts to study the stellar content of this inner spheroid cluster .
The horizontal branch ( HB ) of NGC6287 contains stars spanning a broader range of temperatures than that of NGC6341 .
NGC6287 is thus the only known member of the metal-poor inner spheroid to deviate from the HB morphology versus metallicity relation defined by other clusters in the inner Galaxy .

The clusters are paired according to metallicity , and the near-infrared CMDs and luminosity functions are used to investigate the relative ages within each pair .
The near-infrared CMDs provide the tightest constraints on the relative ages of the classical second parameter pair NGC5272 and NGC6205 , and indicate that these clusters have ages that differ by no more than \pm 1 Gyr .
These results thus support the notion that age is not the second parameter .
We tentatively conclude that NGC6287 and NGC6341 have ages that differ by no more than \pm 2 Gyr .
However , the near-infrared spectral energy distributions of stars in NGC6287 appear to differ from those of stars in outer halo clusters , bringing into question the validity of this age estimate .

Key Words : Galaxy : Globular Clusters : Individual : NGC5272 , NGC6205 , NGC6287 , NGC6341 – Infrared : Stars