The HET has a roughly +/- 90 degree rho offset rotational capability relative
to the parallactic angle for a given observation.
If you wish to query the parallactic angle or the feasibility of any desired
slit position angle for a planned observation, use
the LRS position angle calculation tool.
Position Angle Calculator
Last updated: Sun, 08 Jan 2012 02:08:12 -0600 caldwell