The Environmental Impact of Observatories

Astronomy's impact on society goes beyond philosophical reflections upon our place in the universe, of course. Today's observatories, whether located in orbit or at the highest altitudes on the Earth, have an impact on our environment. Since state-of-the-art telescopes require dark skies, high altitudes, and dry climates, Earth-bound astronomical observatories are located in some of the most otherwise undisturbed environments on the planet. As a result, there have been periodic clashes between...

Space Infrared Telescope Facility SIRTF

The fourth and final Great Observatory was scheduled for launch in April 2003. This instrument will provide a view of the universe in the infrared, with wavelength coverage from 3 to 180 microns, a portion of the spectrum dominated by emission from dust and relatively cool objects. It was planned to be deployed in an Earth-trailing, heliocentric orbit and have a lifetime of 2.5 to 5 years it will employ the next generation of large-format infrared detectors. As a fundamental research tool in...

Roger A Chevalier

Roger Chevalier is a theoretical astrophysicist at the University of Virginia, where he is the W.H. Vanderbilt Professor of Astronomy. He was an astronomer at Kitt Peak National Observatory before becoming an associate professor at the University of Virginia in 1979, where he has been since. Dr. Chevalier's research is in the area of theoretical astrophysics, in particular supernovae and their interaction with their environments. Chevalier is a member of the National Academy of Sciences and has...

What Are Dark Matter and Dark Energy

Astronomers have come to the stunning conclusion that we don't know what most of the universe is made of. These unknown components of the matter and energy in the universe are referred to as dark matter and dark energy. Dark matter has been hypothesized since the rotation curves of galaxies suggested to Vera Rubin in the 1960s that there was more mass in galaxies than was apparent in their stars and gas. In a now-famous result, Rubin proposed that there was some as-yet-unknown form of matter...

The Very Large Array VLA

Operated by the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, the VLA celebrated 20 years of operation in 2000, having become fully operational in 1980. Since that time it has remained the largest radio telescope array ever constructed. The VLA is composed of twenty-seven 25-m radio dishes mounted on fixed piers the telescopes are moved on railroad track arranged in a large Y shape (Figure 2.3). The dishes are moved through four configurations, known as A, B, C, and D. The...

Frazer N Owen

Frazer Owen earned his B.A. from Duke University and his Ph.D. from the University of Texas at Austin in 1974. He is currently a tenured scientist at the National Radio Astronomy Observatory (NRAO). Owen was involved in the initial organization of the Millimeter Array Project and served as Coordinator or Project Scientist between 1981 and 1998. The project, originally involving only NRAO, is now an international U.S.A Europe Japan project and is called the Atacama Large Millimeter Array (ALMA)....

Active and Adaptive Optics

Segment Mirror Active Optics

Large objects are inherently structurally unstable. Skyscrapers, for example, wobble, but their design ensures that the building will hold together under all normal weather conditions, and a certain swaying is tolerated since even steel flexes when a force is applied. Large telescope mirrors are very heavy. Although they are made of glass, a thermal insulator, they still expand and contract slightly as the temperature changes. They also flex, depending on their angle relative to the ground....

Sky and Telescope

Sky and Telescope is a monthly magazine intended for a popular readership. Like Astronomy, it has regular monthly columns, book reviews, reviews of telescopes and instrumentation, news items, and longer articles. It also includes several observing-related columns and a monthly observing guide. 49 Bay State Road. Cambridge, MA 02138 United States of America Telephone 800-253-0245 Fax 617-864-6117 Email For full listing, see

Advanced XRay Astronomy Facility AXAFChandra

Launched on July 23, 1999, the third of NASA's great observatories, the AXAF Chandra is designed to study our universe in X-rays. The working name of the observatory was the Advanced X-Ray Astronomy Facility, but the telescope was renamed (after an open naming contest) in honor of the famous Indian American astronomer Subrah-manyan Chandrasekhar. Chandrasekhar provided a great deal of the theoretical underpinnings that describe the emission of X-rays from astrophysical objects he won the 1983...

Green Bank Telescope GBT

Operational since August 2000, the Green Bank Telescope, operated by the National Radio Astronomy Observatory, surpasses the Effelsberg 100-m as the largest steerable radio telescope in the world (Figure 2.8). Capable of observing at the highest possible radio frequencies, the GBT observes (under ideal conditions) at frequencies up to 80 GHz. The GBT has an unusual shape, resembling the small dishes that attach to homes to receive satellite television. Most radio telescope primary surfaces are...

Conclusion

These four vignettes provide a brief glimpse into the careers of individuals who began working in pure astronomical research and branched out into other areas, some more traditional than others. What is evident is that none of the people waited for change to come to them but took advantage of their situation and skills to launch out onto an alternate career path. They enjoy an exciting work environment, financial freedom, and a more constrained work environment. Astronomers can and do succeed...

Selection Of Astronomical Associations With Useful Web Links

The following is a partial list of astronomical associations compiled by the AstroWeb html . Agrupaci n Astron mica de Madrid AAM . http www.iac.es AA AAM ing.html Amateurs Astronomes du Luxembourg AAL . http www.aal.lu American Association for the Advancement of Science AAAS . http www. aaas. org American Association of Amateur Astronomers AAAA . http www.corvus.com American Geophysical Union AGU . http earth.agu.org American Institute of Physics AIP . http www.aip.org American Mathematical...