Pointing Issues(?)

Friday, December 6, 2019 6:10 AM

Problem(s) Encountered:

Lost pointing big time at the end of the night. Kept resetting the offsets to the wrong objects. When I set the telescope to zenith in the end, it was visibly not at zenith, especially in DEC.  Moved the telescope to zenith by eye (using the orange tape on the telescope for RA and a spirit level for DEC). The zenith distance according to the TCS after I did that was 4.7 as opposed to 0.2 as it usually is. Decided to see if my by-eye zenith offset was decent by slewing to a nearby bright star.  Couldn't find it. Slewing back to zenith put it in the position I had it. I left it at that, so significant improvements to pointing still need to be made.

Solution:

Not sure what was going on with this as things improved by the next day.  In this event, perhaps stowing and cycling the TCS GUI, or even TCS PC (reboot) may be in order.  If objects are consistently off, a procedure for zeroing offsets has been produced by Rupert (MDM):

1) Center a bright star on the guide camera (making sure to click the “center” option in the JSkyCalc guide star window and centering the MIS guide probe)
2) In the TCS window, open the “Telescope” drop menu, click “Initialization,” then the “Telescope Position” tab
3) Click the “Use Telescope Position” button, then “Apply” 

This may also be of some help.