Sunday, November 6, 2011

Telescopes and Snow

This past Thursday my Observational Astronomy class got to go on a field trip to Mauna Kea, where we were treated to tours of three of the observatories up there: the Gemini North facility, the NASA Infrared Telescope Facility, and Hōkū Kea, the telescope that will eventually be for undergraduate students at UH Hilo when they finish fixing it.

We've had quite the storm system washing over the island this past week, so there was actually snow on Mauna Kea when we went up -- and not just "small piles in places the sun hasn't melted yet", but "a pretty good covering". Since I could probably count the number of times I've been around snow on my fingers and toes, it was pretty impressive to me.

Puʻu Hau Kea (Cinder Cone of White Snow)

Looking back whence we came.

Puʻu Makanaka (the large one. I don't know what Makanaka means, perhaps a proper name)

From left to right: Canada-France-Hawaii telescope, Gemini North, the UH 88-inch, the United Kingdom Infrared Telescope, and Hōkū Kea. All looking very cold.

Part of the Sub-Millimeter Array, standing staunchly amidst the cold.

Having gotten all those distracting pictures of frozen water out of the way, I can proceed to describe the actual objects of our tour. Our first stop was the Gemini North telescope, one of two identical 8.1-meter (that's 27 feet) telescopes built and operated by a consortium of countries. The other, Gemini south, resides in Chili, so that between them the two observatories cover almost the entire night sky. The two domes are identical, and are an imposing sight close up:

The Frederick C. Gillett Gemini Telescope dome, up close.

It's hard to capture the sheer size of a telescope that has more area than the floor of my room in one shot, but I tried. The Gemini telescope is similar in many ways to the Subaru telescope, which is almost the same size. For some reason, they're even painted suspiciously similar shades of blue. I did my best here:

The Gemini North telescope. It is huge.

Since it can be hard to appreciate something when you have nothing mentally to compare it to, have another shot with some crew members working in it (that big box they're standing around is an instrument they're about to put on telescope, and yes, it's so big that they're standing on it):

Removing one instrument and swapping in another.

From Gemini we moved to the NASA Infrared Telescope Facility, a 3-meter (9.8 feet) telescope built exclusively for infrared viewing (many of the optical telescopes on Mauna Kea such as the Keck twins, Gemini, Subaru, etc. have the capability to do some limited infrared observing, but IRTF is one of the two telescopes built exclusively for it). IRTF was originally built to support the Voyager missions and to this day at least half of its observing time is taken up by planetary research. Because of this it has a somewhat unusual mount called an English yoke equatorial mount. It's something like two tuning fork stuck with their open ends together, with the telescope free to rotate in between. The advantage of this design is that it is much easier to observer objects that are very near the zenith than would be possible on a regular alt-az mount such as most of the large telescopes on Mauna Kea have.

The NASA Infrared Telescope. Note that same shade of blue paint at the bottom.

Here's another shot from below showing the telescope nestled between the two arms of its yoke:

Showing off the telescope's unusual mount design.

Finally, we ended our time on the summit with a brief tour of Hōkū Kea. It's a mere 0.9 meters, and the entire dome area is probably smaller than Gemini's mirror. It's also apart for maintenance at the moment with the mirror being down for some work, so I didn't get any interesting pictures. There wasn't much to see besides the empty tube, although it too was painted that same shade of blue. I actually asked people at each telescope if there was a reason for the color, but all I got were blank stares so I still don't know. Maybe it was just cheap.

Anyway, after our frosty tour we left to return to the warmth of Hilo, but not before I captured one more snowy landscape in memory:

Looking to the south-west, Hualālai is visible off in the distance through the clouds.

Addendum: If you've read this far you must like pictures, so you may like to check out the post directly before this one. I re-reduced my Andromeda Galaxy picture, and I think it came out a lot nicer. I added it to the post, so you can see both of them and compare. A hui hou!

1 comment:

  1. Ooooh, how pretty!!

    I really want to get up to Mauna Kea, but I don't have any nights off. :( So instead I will enjoy your pictures!

    ReplyDelete

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