Shane 3-m Telescope Pointing Limits
Pointing limits are subject to change in response to changing operational constraints. The limits published here are guidelines. Ultimately, responsibility for the telescope, instrument, laser bundle, etc. rests with the Telescope Operator, who has the final say/veto on any attempt to point the telescope, given the prevailing conditions (e.g. safety, operational, meteorological).East Pointing Limit: -05:40:00.
Expressed as an Hour Angle.West Pointing Limit: +03:45:00 (as of September 2024).
Expressed as an Hour Angle.North Pointing Limit: +72.0 degrees (as of May 2018).
As of May 2018, the nominal northern Declination pointing limit for the Shane telescope is: +72.0 degrees. As of February 2025, the absolute northen Declination pointing limit for the Shane telescope is +82.0 degrees. However, due to cable length restrictions, attempting to observe that far north requires extreme caution to ensure no cables are damaged. Advance approval is required to observe north of the nominal northern Declination limit. Approval may be granted on a source-by-source basis by the Directorship or their designated proxy (e.g. Support Astronomers or Head of Telescope Operations).South Pointing Limit: -35.0 degrees (as of May 2018).
The following (pre-2010) image should only be used for approximate guidance.
Find the declination of your target (green lines) and read the zenith
distance (Y-axis) for a given hour angle (X-axis). Note that several
obstructions (horizontal red lines) are encountered before reaching
the software limits (80 degrees zenith distance or 5h 40m hour angle).
Each of these obstructions - lower shutter, windscreen, and elevator -
requires about 5 minutes to be moved out of the way.
The inoperative windscreen was completely removed in early 2010, so it
no longer can cause any obstruction of the telescope aperture.
Support Astronomers Last modified: Thu Feb 20 10:25:56 PST 2025