An Amateur Professional.
By the end of high school Archinal's sights were set on a career in professional astronomy. In 1974 he enrolled at Ohio State University. Although he did well in mathematics, his course load in college physics proved very challenging. At the same time, his professors warned him of the dearth of jobs in astronomy. By the middle of his second year Archinal decided it was time for a change in his career plan. Leafing through the catalog, he noticed that Ohio State was one of the few universities with a geodetic science department. Geodesy, the study of the Earth's size and shape, became a household term when world attention focused on it during the International Geophysical Year in 1956-57. Archinal thought geodesy seemed challenging and interesting, so he switched majors. He received his bachelor's degree in 1978 and then went on to get master's and doctorate degrees. His thesis involved finding ways to improve the measurement of the Earth's rotation. In 1987 Archinal landed a job at the U.S. Naval Observatory in Washington, D.C. Although his work is in geodesy, his official title is Astronomer. So after years of traveling on a different path, Archinal found that his dream of becoming an astronomer came true after all!
Archinal continued his task on precisely measuring Earth's rotation. Today, using data from satellites such as LAGEOS and the Global Positioning System, as well as laser-ranging equipment left on the Moon by Apollo astronauts and the Very Long Baseline Interferometry (VLBI) network, it's possible to detect very minute changes in the Earth's rotation, on the order of a few millimeters a day.
The VLBI uses a global array of radio telescopes to combine signals and form a single "dish" almost the size of the Earth. With the VLBI one can measure the Earth's motion with respect to distant quasars whose positions are determined to very tiny fractions of an arcsecond. An increase of Earth's rotation can be caused by a storm pelting, for example, the Cascade Mountains in the northwestern United States. Such a storm can speed up the Earth's rotation by a thousandth of a second, and atmospheric conditions like El Nino can slow it down. Over a very long period, tidal friction from the Moon and the Sun is increasing the length of the day by 1.6 milliseconds per century. To keep up with the slowly accumulating time error, a leap second is added to many years. Archinal was part of a team that used positions of radio sources determined by the VLBI to establish the International Celestial Reference Frame, from which all other positions in the sky are now defined.
The Pro As an Amateur
Archinal's decision, back in his undergraduate years, not to become a professional astronomer didn't affect his activities as an amateur. In high school he was a lone skywatcher, observing every now and then and reading what he could about the subject. But at Ohio State he joined the OSU Astronomy Club, where he met new friends. "Astronomy clubs are important," Archinal insists. "They get together people with common interests." Over the years, he has remained active in several groups, the most recent of which is with NOVAC, the Northern Virginia Astronomy Club.
On July 5, 1982, a total eclipse of the Moon dominated the North American night. Archinal observed it with fellow club members from the roof of the physics building. The observatory dome grew crowded as students from astronomy classes joined them. Late that evening, Archinal walked two women back to their dormitory. "One of them was interested in talking to me," he remembers. "I found out her name was JoAnne. I called her afterward. Then I dated her and eventually we got married." Early in the morning of their wedding day, September 7, 1985, Archinal managed to catch his first glimpse of Halley's Comet. JoAnne is active in astronomy; she has edited a club newsletter and often attends star parties with her husband.
Being a professional and an amateur at the same time is an unusual combination. But Archinal's activities in each area are quite different. For the last 10 years, Archinal the amateur has been investigating catalogs of deep-sky objects, paying particular attention to objects with multiple names or designations. In 1993 the Webb Society published a monograph he wrote entitled "The Non-existent Star Clusters of the RNGC." In this work Archinal tried to straighten out the inconsistencies regarding obscure star clusters listed in the Revised New General Catalogue. "It's easy to see how these errors occurred," he says. "These clusters were discovered again and again." Archinal verified many of them himself using a 6-inch f/10 reflector. One of the biggest problems, he notes, was to define what an open cluster is. His special interest in open and globular clusters is leading to a full-scale book with Steven Hynes, to be titled Star Clusters. Scheduled for publication in 2000, it will include information on associations and asterisms as well as true clusters.
Archinal has often heard it said that amateurs "don't do anything" - that they don't provide scientific data. "That's a ridiculous argument," he insists. "Amateur astronomy is a hobby. An amateur shouldn't have to accomplish anything. Observing from your backyard alone or with friends, educating the public at star parties and conventions, or contributing useful data are all valid ways of enjoying the hobby. Amateur astronomy should be something you want to do, not something you feel you have to do." As both an amateur and a professional, Brent Archinal has proved his words well.
In their quest to detect the faintest deep-sky object with the unaided eye, Brent Archinal and author David Levy spotted M81 during last May's Texas Star Party.