Pointing Limits
Note that these limits are only guidelines.Positioning of the telescope is entirely at the discretion of the telescope operator based on safety and limits imposed by the mounted instrument or other hardware.
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.
As of May 2018 a new southern Declination limit has been instituted for the Shane 3-m. The southern declination limit is now -35 degrees 0 minutes.
The current (as of May 2018) northern Declination pointing limit of the Shane telescope is 72.0 degrees. Advance approval is required to observe north of this (but the absolute pointing limit due to cable length restrictions is 75.0 degrees, but going that far north requires extreme caution and care to make sure no cables are damaged). 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).
At the actual time of observation, ultimate responsibility for the telescope, instrument, laser bundle, etc. rests with the on-duty Telescope Operator, who has the final say/veto on any attempt to point the telescope, given the prevailing operational and meteorological conditions.Support Astronomers Last modified: Wed May 2 15:32:22 PDT 2018