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


The Telescope

Technical Overview

Object Observability




HRS Instrument Summary

HRS - Details

HRS Configurations

HRS Throughput

HRS Wavelength Calibration


MRS Instrument Summary

MRS Configurations

MRS Throughput

MRS Wavelength Calibration


LRS Instrument Summary

LRS Configurations

Multi-object Unit

LRS Throughput

LRS Spectral Resolution

LRS Wavelength Calibration

Visitor Filter Information

LRS Position Angles

Blind Offsetting

Guide Stars Limits

LRS Update from Gary Hill

Program Preparation

Web Management System

Other HET Documentation