About 44 percent of AAS members in 2009 were affiliated with research universities, and 34 percent were affiliated with national observatories, laboratories, and other federally funded research and development centers (see Table 4.1). The fractions in different work sectors have not varied much over the past 20 years except at 4-year colleges, where the fraction of astronomers has almost doubled (to 15 percent), reflecting the growing importance of introductory astronomy as a gateway science course and as a popular course for non-science majors to fulfill a science requirement.
The annual number of astronomy Ph.D.s awarded in the United States has been fairly constant at about 200 over the past decade, compared with approximately 1,400 in physics and 4,000 in the physical sciences overall. However, increasing numbers of astronomers are receiving their degrees from physics departments. The fraction of astronomy Ph.D.s awarded in the United States to non-U.S. citizens has risen from about one-quarter to more than one-third over the past decade, still