American Association of Variable Star Observers
Coordinates amateur variable star observations for professional research.
The American Association of Variable Star Observers (AAVSO) is an international nonprofit organization founded in 1911. It coordinates, analyzes, publishes, and archives variable star observations made largely by amateur astronomers. The AAVSO creates records that establish light curves depicting the variation in brightness of a star over time, and makes these records available to professional astronomers, researchers, and educators. Professional astronomers do not have the resources to monitor every variable star, making astronomy one of the few sciences where amateurs can make significant contributions to research.
- Founded
- 1911
- Incorporated
- 1918
- Headquarters original
- Norwich, Connecticut, at the residence of founder William T. Olcott
- Headquarters 1931 1953
- Harvard College Observatory
- First building purchased
- 1985
- Current headquarters
- premises of Sky & Telescope magazine (since 2007)
- Executive director as of 2022
- Brian Kloppenborg
- Members and observers
- over 2,000
- Observations in database as of 2019
- over 35 million
- Annual observations received
- nearly 1,000,000
Lore & Background
After AAVSO's incorporation in 1918, it unofficially moved to Harvard College Observatory, which later served as the official AAVSO headquarters from 1931 to 1953. Thereafter, it moved around Cambridge before their first building was purchased in 1985: the Clinton B. Ford Astronomical Data and Research Center. In 2007, the AAVSO purchased and moved into the recently vacated premises of Sky & Telescope magazine. As of September 16, 2022, the Executive Director is Brian Kloppenborg. Before him, Kathy Spirer worked in this capacity for nine months, following the resignation of Styliani ('Stella') Kafka, who was in charge from February 2015 till the ember months of 2021. She succeeded Arne Henden. The previous director for many decades was Janet Mattei, who died in March 2004 of leukemia. The AAVSO currently has over 2,000 members and observers, with approximately half from outside the United States.
Reader's Guide
The AAVSO's significance lies in its role as a bridge between amateur and professional astronomy. By coordinating, analyzing, publishing, and archiving variable star observations made largely by amateurs, it fills a gap that professional astronomers cannot cover due to limited resources. The organization's database, the AAVSO International Database (AID), stored over thirty-five million observations as of 2019, and the International Variable Star Index (VSX) cataloged 10,300,863 variable stars as of November 2023. The AAVSO receives nearly 1,000,000 observations annually from an estimated 2,000 observers and is quoted regularly in scientific journals. Its legacy includes the development of the Hands-On Astrophysics curriculum (now Variable Star Astronomy) in the 1990s with NSF support, and the Citizen Sky project examining the 2009-2011 eclipse of epsilon Aurigae, funded by a three-year $800,000 NSF grant in 2009. The organization also holds training workshops for citizen science and publishes papers with amateurs as co-authors.
Did You Know?
- The AAVSO received its twenty-millionth variable star observation in 2011, its 100th year.
- Minor Planet (8900) AAVSO is named after the organization.
- The AAVSO's first building, purchased in 1985, was the Clinton B. Ford Astronomical Data and Research Center.
- The AAVSO moved into the former premises of Sky & Telescope magazine in 2007.
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