Heading west on I-10 toward Kitt Peak National Observatory, and there were signs of unsettled weather over the mountains of eastern Arizona. A few drops of rain reached my windshield, but most of it evaporated before reaching the ground - virga. en.wikipedia.org/wiki/Virga
You know you're in geek territory in the astronomer dorms. A simple light switch evokes some physics concepts.
MDM (Mich. Dartmouth MIT) Observatory is a mile west of Kitt Peak National Observatory, and would be my home for the next ten days. http://www.astro.lsa.umich.edu/obs/mdm/ The two optical scopes (1.3M and 2.4M) are the smallest domes in the background. Two radio telescopes are also present.
12-meter radio telescope in a plastic-covered dome.
MDM's 1.3-meter scope was built almost 50 years ago. Worm drive on both axes, and a cross axis mount. Today it has servo motors and a CCD, but most of the mount and scope remain unchanged since it's first use in Michigan.
Counterweights are mounted at the north end of the polar axis.
The imaging CCD requires liquid nitrogen twice a day.
This is the RA drive. The servo motor is about the size of my fist. The worm wheel is about five feet in diameter. Also pictured are rollers to keep the worm aligned with respect to the wheel.
The 2.4-meter scope is the largest ever built by DFM Engineering. http://www.dfmengineering.com/index1.html It's a fork mount with friction roller drive.
2.4-meter RA drive. Again, a small servo motor, but this time with several stages of belt/pulley reduction, then the final roller.
At sunset the scopes are opened up and readied for their observing runs. The 2.4-meter can do either spectroscopy or imaging, and the 1.3-meter does imaging.
After sunset you can look east toward Kitt Peak and see the pale red/blue shadow of the earth climbing higher.
The clouds make for a pretty light show, but fortunately they dissipated shortly after dark.
This is what the scope operator spends lots of time staring at. The right screen has the telescope control system, and the left has image display and processing software called up.
Each scope also has an off axis guider (on a moving X/Y stage). Yes, it's an intensified, low light level TV system, not a CCD.
This old guiding technology still works pretty well, but it should be upgraded soon.
Undergrads and TA's in the 2-4M control room. Lots of spectra were being taken, studying fields of new gamma-ray sources from Fermi/GLAST in orbit. Would the students find an optical counterpart to one of them? That can only be answered after you take many spectra.
Careful comparison of the star field with the image displayed by the slit camera - you need to then position the desired target on the slit and start the autoguiding loop. Next is the actual exposure for the spectrum.
This looks like a typical stellar spectrum - probably not a gamma-ray source. Other projects included: galaxy rotation curves, binary stars, planetary nebulae, and a few more that escape me.
It snowed (just a trace) on two nights! Unsettled weather meant that the view west in the daytime was benign, but to the east...
...dark clouds covered Kitt Peak, and there was even some precipitation falling to the desert floor in spots.
A short jog (almost two miles, and 500 feet higher) takes you to Kitt Peak. It's crowded up there. The biggest dome is the 4-meter Mayall scope, which saw first light in 1973.
This building is far smaller than the Mayall 4m
but it houses the WIYN 3.5m
http://www.noao.edu/wiyn/ and in many ways it's a more capable scope.
You can walk down 'inside' the telescope....
The heliostat mirror directs sunlight....
...down to the main mirror, and then back up...
...to a flat mirror that directs the light to various instruments.
The Kitt Peak visitors center has various displays, such as a series of gas discharge lamps that show spectra when you look through a transmission grating.
We had set up some small scopes for visual observing because the big scopes only were used with CCD's.
Students enjoy sunset before starting work on the night shift.