The Steward Observatory’s Bok 2.3m telescope sits right beside the largest telescope on Kitt Peak Mountain: the Mayall 4 meter. I’ve posted pics of it many times, like here, and here, and here. I’ve walked up to it a few times and gone inside the visitor centre there, but an up-close look at the telescope is usually only afforded to those that are using the telescope. Happily, we met the operator of the telescope and he offered us a chance to see it. This is what it looks like when astronomers geek out over astronomy-type things:
A telescope is defined by its collecting area. For an optical reflecting telescope, this is the diameter of its primary mirror. So how big can these mirrors get? Well, the York Observatory houses a telescope with a primary of 60 centimeters in diameter. I posted a picture of that mirror here when it was taken out for re-aluminizing. But mirrors can get a lot bigger than that. One of the largest mirrors in the world can be found at the Gemini Observatories (one in Hawaii atop Mauna Kea, and the other in Chile), which house telescopes with 8 meter primary mirrors. When the Gemini ‘scopes were being built, the National Optical Astronomy Observatory (NOAO) painted a circle on one of its outer walls the exact diameter of the primary mirrors of the new telescopes. Here’s me standing in front of that circle.
The largest optical reflecting telescope on the planet is the Gran Telescopio Canaris, in the Canary Islands. Here’s a list of the runner ups.
Having fun with a GoPro Hero3 camera. Before any night time observing occurs, the telescope and instrument require set up, and calibration images need to be taken. We arrive about an hour before sunset (which was roughly 6:15pm local time during the week I was there) to start setup. First we fill the instrument’s dewar with liquid nitrogen to keep the instrument cold. Then we do calibration images. This time-lapse shows the hour of set up and calibration we did on one of our observing nights.
I couldn’t capture a time-lapse of the whole evening because the GoPro doesn’t work well at night. GoPro’s are designed for day time use. Ah wells.