University of Texas Austin - Cactus Yearbook (Austin, TX)

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1 TEXAS SUNSET: The sun goes down on the 30-inch telescope. The dome was opened well in advance to equalize internal and external temperatures. STARSTRUCK: Time exposure of the 107-inch and 36-inch telescopes reveals the nightly motions of the stars. CONTEMPLATION: Be- ginning a night ' s work, Edward Robinson, professor of astronomy, concentrates as he focuses the 107-inch tel- escope. McDonald Observatory 21

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The Stars at Night Are Big and Bright. . . They awoke in the afternoon and be- gan their shifts at sundown. They worked all night long, until bedtime at first light. This routine may remind one of po- lice officers on a graveyard beat or stu- dents studying for final exams, but in fact it occurred far away from the bright lights of Austin. It was a typical night ' s work for astronomers at McDonald Observatory. The professors and students who came and went at the West Texas site were housed at the transient quarters. This facility served as a place to sleep and eat during ob- serving runs that could last days or even weeks. Because of the night schedule, sleeping and eating patterns were re- versed, with dinner often being the first meal of the day. I usually get up at two and then have a bowl of cereal, and that does me till dinner, Scott Kleinman, graduate student in astronomy, said. After dinner, the telescope domes were opened an hour before twilight in order to equalize the interior and ex- terior temperatures. If a dome ' s inte- rior were warmer than its exterior, ris- ing air could adversely affect observation quality. After calibration, astronomers spent the rest of the night collecting data. If it was too cloudy, they would wait until morning if necessary for the skies to clear. Telescope time at the observa- tory had to be reserved three to four months in advance, so astronomers used every available moment until dawn. Dedicated on May 5, 1939, McDonald Observatory had served as a leading center of astronomy research for fifty years. The observatory was built on a bequest from prosperous Par- is, Texas, banker and amateur scientist It ' s easy to be a good astronomy teacher, because all of us are very evangelistic about astronomy. We all love it, and we all want to convey our love of it to other people. Frank Bash, director William Johnson McDonald. The West Texas site had a number of features which endeared it to the orig- inal builders. Harlan Smith, professor of astronomy, who completed a 26-year tenure as director of the observatory in August, 1989, said, McDonald has vir- tually everything you would want in an outstanding telescope site. A number of factors contributed to the observatory ' s excellent viewing con- ditions. First, the cloudless skies over the Davis Mountains allowed viewing on about two-thirds of the nights during the year. The calm air that typified the weather at the obser- vatory meant that light from distant stars was distorted very little by atmos- pheric turbulence, a condition astrono- mers referred to as good seeing. The site ' s 6,800- foot altitude kept the telescopes above most of the obscuring atmosphere, and the relative remoteness of the location ensured that the skies were not illu- minated by city lights. This problem, called light pollution by astronomers, plagued most U.S. observatories due to encroaching cities. Lastly, the observa- tory ' s latitude allowed for viewing of most of the southern sky. The list of instruments atop Mount Locke near Fort Davis included 107-, 82-, 36- and 30-inch optical telescopes. The size of a telescope determined how much light astronomers could gather. Smith used the analogy of people in the desert making a rain collection of a poncho. The bigger the poncho they can spread out to catch the raindrops and funnel the water down through a hole in the bottom to a bucket, the more water they collect, Smith said. Sim- ilarly, the larger telescopes were able to detect more of the photons arriving from space. story and photos by Hannes Hacker TAKE A CLOSER LOOK: Scot Kleinman, grad- uate student in astronomy, makes an adjustment on the 36-inch telescope. Minor adjustments sometimes had to be made during the afternoon to save observing time at night. 20 McDonald Observatory

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WATCHFUL EYE: Katia Cunha, doc- toral candidate in astronomy, keeps the 82-inch telescope pointed at a distant star for a spectroscope reading. ON STANDBY: Showing the 101-inch tel- escope, Marc Wetzel, physics under- graduate from UT-Arlington, conducts one of the daily tours of the obser- vatory. 22 McDonald Observatory