The structure of a very bright ( M _ { V } = -10.9 ) globular cluster in NGC 1023 is analyzed on two sets of images taken with the Hubble Space Telescope .
From careful modeling of King profile fits to the cluster image , a core radius of r _ { c } = 0.55 \pm 0.1 pc , effective radius R _ { e } = 3.7 \pm 0.3 pc and a central surface brightness of \mu _ { 0 } ( V ) = 12.9 \pm 0.5 mag arcsec ^ { -2 } are derived .
This makes the cluster much more compact than \omega Cen , but very similar to the brightest globular cluster in M31 , G1 = Mayall II .
The cluster in NGC 1023 appears to be very highly flattened with an ellipticity of \epsilon \approx 0.37 , even higher than for \omega Cen and G1 , and similar to the most flattened clusters in the Large Magellanic Cloud .