LOCATION OF THE 0.9M TELESCOPE
The 0.9-m telescope is located on the southern ridge of Kitt Peak in the Quinlan Mountains, about 50 miles southwest of Tucson.
Prior to starting up the systems or moving the telescope the safety walk-through
needs to be done to ensure that systems are at nominal operating conditions
and that one can safely move the telescope.
Turn off the white light at the entrance.
Check cables around telescope - make sure none are strained, pulled out.
Bring up the control system on Olive if not already up (Select "ACE"
from the desktop)
Use the ladder to remove the mirror cover. Be careful not to bump the flat field lamps.
IF DOING DOME FLATS:
IF OPENING FOR OBSERVING:
Slew the telescope to zenith (Remember to Reset the slew interlock)
Stop your exposure and guiding. Quit the guider software on Moss. If
using S2KB be sure to Disconnect the guide camera before quitting
Use the ladder to replace the mirror cover.
Log out of and exit the TCS control system on Olive (Select User => Logoff from the top toolbar).
Turn off the fan in the loading dock.
When leaving the building please make sure the outside door closes fully behind you.
If this is the last night of your run see the End of Run Checklist for additional shutdown items.
For safety reasons, there are a couple of interlocks in the dome that will disallow slewing of the telescope when people are in the dome or the platform is raised. The telescope will also stop slewing if an interlock is tripped during a slew. This only affects a slew - all other functions (telescope tracking, guiding, dome tracking, etc.) will still function normally when an interlock has been tripped.
When an interlock has been tripped a small window will appear on the TCS.
The platform interlock is automatically reset when it has been fully lowered. To reset the interlock caused by the motion sensor, click the Reset button in the small window. Keep in mind that you will need to reset this each time you walk onto the platform.
In order to keep the CCD cold the dewar needs to be filled on a regular basis with liquid Nitrogen. The observer is responsible for filling the dewar when S2KB is in use, but the WIYN OA will fill the dewar when Mosaic is on the telescope. The telescope does need to be at the zenith park position in order for the liquid nitrogen fill line to reach the instrument so be sure to park it there at the end of each night. The Site Manager will review proper liquid nitrogen handling procedures with you if appropriate.
S2KB holds approximately 8 hours, meaning it will be necessary to fill the dewar every 8 hours. If the dewar is allowed to warm up it may take quite a while for it to cool down again and could cause the vacuum to go soft, resulting in even shorter hold times. So please be diligent about filling it. However, Mosaic will hold for 12+ hours so you shouldn't need to interrupt observations to have it filled.
To check the temperature of the S2KB dewar and camera type "ccdinfo" in the Data Acquisition window. The last two lines displayed indicate the dewar and camera temperatures. Nominal temperatures are: CCD= -98 Dewar= -191. If the dewar begins to warm up you should stop your observations and fill it with liquid nitrogen, even if it has been less than 8 hours since the last fill.
If the dewar has warmed up, check the troubleshooting section Dewar Warmupsfor recovery procedures.
Mosaic's temperatures are constantly displayed on the Mosaic GUI. If the dewar begins to warm up mountain personnel will be notified by email and will come to fill the dewar shortly.
The dewar is usually filled at the beginning and end of each night with liquid nitrogen (you may have to interrupt observations during the night to make sure S2KB is filled every 8 hours). There is a fill line and valve mounted on the side of the telescope pier that runs down to the 230L dewar in the loading area where the liquid nitrogen is stored. The fill line should be precooled before attaching it to the instrument - simply open the valve on the observing floor and point the fill line away from you. Close the valve when liquid starts to spew out of the line and attach the line to the instrument. Liquid will spill out (of the overflow holes between the dewar and the nut attaching the line to the instrument) when the dewar is full. Close the valve when it is full and replace the cap on the dewar.
For more help on filling a dewar, see the href="http://www.noao.edu/0.9m/observe/manual/appendices.html#dewar">Dewar Filling Tips and Tricks section in the Appendix.
There are two small video cameras fixed in the dome - one located on the
south wall and the other just below the stairs above the motion sensor. The
cameras allow you to view the telescope and platform area when there is light
in the dome. (Nothing will be visible on the cameras during the night
or when the lights are off.)
To help improve the seeing at the 0.9m an exhaust fan has been installed along the polar axle. This will draw air across the primary mirror, alleviating pooling of hot air on the mirror.
If the outside humidity is greater than 70% this exhaust fan should not be used. For more on how to check your humidity see the weather section.
Currently, operation of the fan is done manually. (Weather permitting) the fan should be turned on when opening the dome for the evening, and turned off when closing in the morning. The fan is located on the observing level behind the telescope pier. You will need to plug in the electrical into the socket on the wall to turn it on and uplug it to turn it off.
In order to determine the effects this fan is having on seeing we request that observers closely monitor seeing throughout the night, noting the seeing in the nightly observing report. In addition, we request that observers check the seeing near the end of the night on a very short, unguided exposure (e.g. on a standard star field) on a field that is at less than 2 airmasses. This seeing measurement should be noted in the comments section of the nightly observing report
In cases where the wind has not reached the closing limit of 45mph, but the telescope shake is affecting science, a wind screen is available for use. The controls are located to the left of the dome slit. In order to reach the controls the dome must be rotated to face the slit west. Make sure to turn the power on for the controls before use and turn it off after moving the screen into place.
The WIYN 0.9m observatory uses a dry air system in order to keep the dewar window from frosting up. Normally, this system is active 24 hours a day and does not require the attention of the observer outside a quick visual check at the beginning and end of a night to make sure it is running. The compressor for this system is located in a small exterior room on the very south side of the observatory.
Operation of this system should be checked at the beginning and end of each night as part of the start-up/shutdown procedure. To check its operation, go to the computer room and find the moderately sized blue box mounted on the wall near the black air compressor. The power button should be in the "On" position, the green light should be illuminated on the panel, and ONE of the two pressure gauges should read just short of 40psi. This system alternates between two internal pressure tanks, so only one of the two pressure gauges should read any pressure at a time.
See the Troubleshooting section of this manual for problems related to the dry air system.
The 0.9-m at sunset with 7 of the 11 ventilation louvers visible.
In August 1994, dome vents were added to the 0.9-m dome to provide much improved flow-through ventilation as part of an image quality improvement project. The 11 individually controllable vents are located opposite the dome slit to allow the dome air to flush several times per minute under typical wind conditions. Rapid flushing helps eliminate warm air pockets from forming in the dome, which in turn, reduces convection that would otherwise compromise image quality (that is, "seeing").
Normally, some complement of vents will be opened at the beginning of the night, around sunset, and closed when the telescope is closed. If the dome is iced up, the vents may need to be broken free.
Based on limited testing, the dome flushes adequately with about half the vents open during mild wind conditions. You may wish to open every other vent.
Under the following conditions the observer should restrict the air flow by closing some or all of the vents.
If the air is very calm, less than about 5 mph, you may wish to open additional vents.
Detailed Manual Operation of the VentsIn this mode, one can open or close any or all of the 11 vents individually. The vent control panel consists of four types of switches as described below. The term "ensemble of vents" refers to those vents whose "Together-Off-Separate" switches are set to "Together".
Last updated 03/05/09 hlm