Telescopes & Research, Page 3

George Coyne, on the balloon polarimetry program

My original work with Tom Gehrels was great. We had a nice team there [including Krzysztof Serkowski, Martin Tomasko, and graduate student Ben Zellner]. We would fly balloons, because these were early days of the space program, so you couldn’t send a rocket off into space at that time. But you could send up balloons, which would get up above a lot of the Earth’s atmosphere, and do research in infrared from balloons.

There was an agency of the federal government called the National Center for Atmospheric Research, NCAR. They had a site in Northern Arizona and a site in Palestine, Texas for launching these things. One of the exciting things we’d do is once or twice a year we’d go to these sites and we’d fly these balloons. They were very early days so even methods of collecting your data were being developed.

Then the polarization went into all kinds of new and exciting areas. We first discovered that some stars give off polarized light. That’s very important for knowing the kind of structure of the atmosphere of the star. Then we found that some galaxies give off polarized light, because they have very energetic sources at their center and that light is scattered as it comes out from the galaxy. So that whole research in polarimetry began to broaden from planetary into all kinds of other objects. They were the early days of my research.

Don McCarthy, on observing with Frank Low

Frank Low was always fun on observing runs, because he has this tremendous insight into what problems were. We were just exploring. We measured some of the first sizes of astronomical objects. That became my thesis, and it led to me doing the same kind of work at the Multiple Mirror Telescope [MMT], which back then was six separate 72-inch telescopes.

No one had really ever envisioned that you could adjust the way light bounces to each telescope so that all those distances were equal, so that instead of the telescope performing as six separate 72-inch mirrors, it performed as one 6.5-meter telescope that you just used six parts of. We learned how to make those adjustments. That was the start of a different kind of interferometry, which you have today at many different facilities where the telescopes are separate and you bring the light together.

One day we were driving up the MMT road [on Mt. Hopkins] for one of these observing runs, and this was before the MMT was dedicated. They had what were called Friday Night Specials: They would have Friday nights devoted to scientists who would come up there and try to do experiments under non-ideal conditions. We were doing one. So Frank’s driving us up the mountain, which is a very scary road and was scarier then before they paved a lot of it.

We go around a corner—it’s a one-lane road—and this big Greyhound bus comes down suddenly from the other side. Frank’s reactions were very quick: He took us right into the side of the mountain; not on the outside of the mountain but the inside.

The Greyhound bus—there was no way that momentum was going to stop. They were practicing for the dedication of the mountain the following week or two. Those Greyhound buses were out there without anyone’s knowledge, just learning the road.

The interferometry actually began on the 21-inch telescope here right behind us. Frank gave instructions that if I ever got it working to phone him no matter what time it was. So I remember 3am phoning him when we had the first interferometer working. That led to the MMT eventually, and to the design of the Large Binocular Telescope because it’s two separate mirrors whose light you want to combine. So the legacy of that was pretty huge, and we had some fun times doing it.

There aren’t many times when you have a place or a group of people who start something completely new. It’s getter harder and harder to do, I think. What Frank Low did with infrared astronomy is simply not common or maybe not possible today: To make a new kind of detector or instrument here on your desk, take it to a mountain, put it on a telescope and discover that Jupiter has its own energy source. That’s just not common. To explore a whole new realm of the electromagnetic spectrum was really odd. Or to start a whole new way of exploring, namely the space program, which LPL figured in so prominently, is really amazing. It’s not like it was in the LPL days of infrared astronomy, where you put together a detector and haul it up a mountain and you’re doing an observation and discovering something all in the same day.