We use two-band imaging data from the Advanced Camera for Surveys on board the Hubble Space Telescope for a detailed study of NGC 1533 , an SB0 galaxy in the Dorado group surrounded by a ring of H i .
NGC 1533 appears to be completing a transition from late to early type : it is red , but not quite dead .
Faint spiral structure becomes visible following galaxy subtraction , and luminous blue stars can be seen in isolated areas of the disk .
Dust is visible in the color map in the region around the bar , and there is a linear color gradient throughout the disk .
We determine an accurate distance from the surface brightness fluctuations ( SBF ) method , finding ( m { - } M ) = 31.44 \pm 0.12 mag , or d = 19.4 \pm 1.1 Mpc .
We then study the globular cluster ( GC ) colors , sizes , and luminosity function ( GCLF ) .
Estimates of the distance from the median of the GC half-light radii and from the peak of the GCLF both agree well with the SBF distance .
The GC specific frequency is S _ { N } = 1.3 \pm 0.2 , typical for an early-type disk galaxy .
The color distribution is bimodal , as commonly observed for bright galaxies .
There is a suggestion of the redder GCs having smaller sizes , but the trend is not significant .
The sizes do increase significantly with galactocentric radius , in a manner more similar to the Milky Way GC system than to those in Virgo .
This difference may be an effect of the steeper density gradients in loose groups as compared to galaxy clusters .
Additional studies of early-type galaxies in low density regions can help determine if this is indeed a general environmental trend .