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Turpol start-up in the evening - Nordic Optical Telescope

TURPOL start-up in the evening

  • Check that cooling system is operating (i.e. that the temperature is between -16 and -21 degrees), by looking at the display of the compressor unit on the observing floor. If not working, contact staff immediately! Note that cooling is needed for the RI channels only.

  • While you are up there, make sure that the dark slide is closed (knob in OUT position).

  • Turn up the high voltage power supply (-1150 V for the UBV supply and -1800 for the RI supply). This should be done 3-4 hours before observations start to get the required stability for accurate photometry (for polarimetric results, however, a few minutes will do). NB! Do not put too high a voltage on the tubes, as this will cause permanent damage! Also, do not turn up the high voltages in very humid conditions. If in doubt, confer with staff.

  • On the PC labelled MIRIAM, ensure that you have booted into the DOS session and then type C: and CD \TURPOL. If you need good timing, set the PC clock every evening. Make your own sub-directory (MD name), go there and start the polarimeter control programme by typing pp. Note that some default parameters are set (linear polarimetry, integration time 10s, number of cycles 4) which you may want to change. Open a datafile for this night under the FILE menu, and name it according to evening date, e.g. p010520.dat for the night starting on the 20th of may 2001.

  • Start-up the diaphragm viewing facility (using the ST-4 CCD) by powering on the portable PC (knob on the left-hand side). Go to directory ST4 by typing cd ST4. Type ccdtrack. Check here for Using the ST-4.

  • After telescope power-on and dome opening (see the Cookbook for details), set field-r 0 on the TCS, and once it is dark enough, switch on the guide TV by the TCS command tv-on. Make sure it is dark enough, go to the dome, turn domelights off, and open the Turpol dark slide (put knob in IN position). NB! Put all domelights off, and be very careful with the flashlight when having opened the dark slide!

  • Load your object catalog on the TCS, set auto-positioning-full, for the automatic guide star acquisition, and you are ready to observe with Turpol. For the time being it is a good idea to set manual-tv-focus with turpol, sinc the automatic-tv-focus still does not work very well.