The amount of programming and orbital changes needed for this is not feasible.
For the hubble to point at something, I'd imagine it needed to station-keep and burn some hydrazine.
If you did infinite numbers of 5-10 min studies, you'd burn right out of the fuel store of a spacecraft before you'd get anything done.
From what I hear, hubble telescope times are scoped out, planned out a year or several years in advance - the telescopes and scientific instruments need to be programmed, the spacecraft needed to be moved/pivoted to aim at the right part of space, communications times needs to be booked with receivers/ground stations across the entire Deep Space Network so you can receive the data.
It's nontrivial - if you booked 5-10 min at a time you'd have wasted your most precious resource.