Saturday, March 3, 2012

Mauna Kea Telescope Tour

A view of Mauna Loa from the HP.
Recently, I had a great opportunity to visit some of the telescopes up on Mauna Kea as part of my Observational Astronomy class. While it is certainly possible for any one to go up the mountain, and perhaps even get a basic tour, we were given an insiders tour into both the Gemini and CFH telescopes. I also had my first opportunity of checking out Hoku Ke'a, the new student telescope for us Astronomy students at UHH. Special thanks to Dr. Josh Walawender, my prof who arranged the trip and took us up there.

Looking toward Hoku Ke'a and Mauna Loa.
We started the day by taking a tour of the Hoku Ke'a dome. I would say "telescope" except for the fact that the telescope isn't really there. Unfortunately, this new scope, which is being build specifically as a student telescope, is many years behind schedule, both from the original construction and installation as well as from problems discovered after it had been installed. While the scope was supposed to be operational many moons ago the hope is to start doing some actual observations by the end of the summer. Too bad for all the students who came before, excellent timing for me. As a matter of fact, I am helping Josh out with some aspects of getting the scope running (more on that later).



Josh explaining the worm gear. We are standing underneath
where the mirror itself would be placed. Note that the mount
is currently rotated 180° since the mirror is absent.

Since Hoku Ke'a is in a non-operational state, we were able to get a closer examination of the mount structure that is being used. Josh pulled off some panels to explain the worm gear that is used. Basically, the larger gears which drive the RA and Dec are controlled by the smaller worm gear, which allows for precision control, something on the order of arcseconds. One of the goals for the large(r) scopes is to have total information about the scope, dome, environmental conditions, etc. As more and more scopes go toward remote observations, which is the plan for Hoku Ke'a, it becomes increasingly important to know the state of nearly every component. One such example is the plan to install monitors on the worm gear such that we can know the exact position of the gear itself and how that relates to the RA/Dec of where the telescope is pointed. Another example is the project I am actually working on now, which will have some cameras pointed at the actual scope itself so we can do some image analysis on the conditions that exist inside the dome at any given moment. More on Hoku Ke'a will certainly be forthcoming as I write more on this project (and hopefully more) that I will be working on.

After a lunch at the summit (thanks to the summit crew for providing a vegan option for me!) we were taken inside the Gemini scope. To say that being inside the dome and seeing the inside of Gemini was incredible would be a vast understatement. This is a very vast structure consisting of many, many parts, all delicately intertwined. Complex Systems is the word they like to use.
Underneath the primary mirror at Gemini North.
Lately I have been struck by just how incredible some of our (human beings) engineering accomplishments are and it was truly remarkable to be literally standing inside one of the engineering marvels. Not to mention really, really cold. Since everything has a latent thermal energy, including the glass (it's not really glass, but still) of the mirror itself, it is critical to keep the inside of the dome at a constant temperature with respect to the viewing conditions. So, this means keeping everything inside the dome at the same temperature as the outside night air, when observations are done. So, this mean cold. Really cold.

We were given a tour of the casing room, where they do work on the mirror when needed. We saw the inside of one of the four control rooms (one is down by the University and the other two are, I assume in Chile at Gemini South), which very seriously looked super high-tech. No doubt, that is what a Science room should look like, with monitors and dials and images and lights and bells and whistles. Later, as we toured CFH, it was interesting to see their summit control room, which is slightly older and looks like serious Science from the 60s. It's kind of like the difference between Kirk's Enterprise and Picard's.

We were also taken up onto the 5th floor, looking down onto the primary mirror. It was, of course, covered in the daytime but we got to walk around the rafters and get a close-up look at the area. While we were on this tour they were doing some maintenance work on the dome itself and I managed to snag a good photo of the partially open dome looking out toward a beautiful crescent moon.
Opening of the dome inside Gemini North with a beautiful
crescent moon positioned in just the right spot.

Control room for CFH. You can almost hears the beeps, bings,
and whirs of Science! Note even the analog dials.
Our tour of CFH was equally remarkable. CFH is one of the older scopes on the summit but because of aggressive, and intelligent, maintenance and updates by their engineering crew, they are still producing incredible images and remain a significant player. However, it was very telling to see the difference in technology that can happen in 10-20 years time. While Gemini was very clean and controlled, CFH was more of a working-engineers paradise, with exposed wires and machines, grease in the corners, old paint on the walls. Also, because CFH has gone completely to remote operations, as opposed to Gemini which is still mainly classical observation, it was rather strange since there was not a single other person in the whole building. While Gemini crawled with some astronomers and day-crew and people doing things, CFH sat silent and dark. Again, this is not a reflection on the actual science coming out of either of these scopes as they are both incredibly remarkable and productive; just an interesting note on the differences between the two.

CFH primary mirror with the MegaCam installed
in place of a secondary mirror. Also a good view
of the horseshoe mount.
There were many more details and I learned a lot on the tour. Again, it was incredibly fascinating and an outstanding opportunity for me. Special thanks to Josh for arranging everything as well as the crews of Gemini and CFH! Watch the sky!