The American Association of Variable Star Observers (AAVSO) is an international nonprofit organization, founded in 1911, focused on coordinating, analyzing, publishing, and archiving

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...

observations made largely by amateur astronomers. The AAVSO creates records that establish light curves depicting the variation in brightness of a

star A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make ...

over time, and makes them available to professional astronomers, researchers, and educators. Since professional astronomers do not have the time or the resources to monitor every

astronomy Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...

is one of the few sciences where amateurs can make genuine contributions to scientific research. During 2011, the 100th year of the AAVSO's existence, the 20-millionth variable star observation was received into the database. The AAVSO International Database (AID) stores over 35 million observations as of 2019. The organization receives nearly 1,000,000 observations annually from around 2,000 professional and amateur observers and is quoted regularly in scientific journals. The AAVSO is also very active in education and public outreach. They routinely hold training workshops for citizen science and publish papers with amateurs as coauthors. In the 1990s, the AAVSO developed the Hands-On Astrophysics curriculum, now known as Variable Star Astronomy (with support from the

National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National ...

(NSF)). In 2009, the AAVSO was awarded a three-year $800,000 grant from the NSF to run Citizen Sky, a pro-am collaboration project examining the 2009-2011 eclipse of the star epsilon Aurigae. Starting on September 16, 2022, the Executive Director of the AAVSO is Brian Kloppenborg. Before him, Kathy Spirer was the Acting Executive Director for nine months, after Styliani ("Stella") Kafka -who was in charge between February 2015 and the end of 2021- resigned. She had taken over from Arne Henden. The previous director of the AAVSO for many decades was Janet Mattei, who died in March 2004 of

leukemia Leukemia ( also spelled leukaemia and pronounced ) is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or ...

The AAVSO headquarters were originally located at the residence of its founder William T. Olcott in

Norwich, Connecticut Norwich ( ) (also called "The Rose of New England") is a city in New London County, Connecticut New London County is in the southeastern corner of Connecticut and comprises the Norwich-New London, Connecticut Metropolitan Statistical Area, ...

. After AAVSO's incorporation in 1918 it de facto moved to Harvard College Observatory, which later officially provided an office as the AAVSO headquarters (1931–1953). After then it moved around

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge beca ...

before purchasing their first building 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.

Minor Planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term '' ...

(8900) ''AAVSO'' is named after the organization.

Current and former members

;Recorders and Directors ;Presidents ;Other members The AAVSO currently has over 2,000 members and observers, with approximately half of them from outside the United States. This list only consists of those with Wikipedia pages.

Publications

* ''AAVSO Alert Notice''.
''Journal of the American Association of Variable Star Observers'' (JAAVSO)
* ''AAVSO Circular'' was published from 1970 until 2000 and edited by

John E. Bortle John E. Bortle is an American amateur astronomer. He is best known for creating the Bortle scale to quantify the darkness of the night sky. Bortle has made a special study of comets. He has recorded thousands of observations relating to more than ...

References

External links

AAVSO websiteThe International Variable Star Index
(VSX)
History of the AAVSO
Space.com, June 28, 2000

article in the January 2007 issue of '' Sky & Telescope'' magazine
Red Hot News… Possible Nova in Sagittarius!
'' Universe Today'', August 9, 2009
100 Years of Citizen Science
(1 December 2010) {{DEFAULTSORT:American Association Of Variable Star Observers Harvard University Amateur astronomy organizations Astronomy organizations Variable stars 1911 establishments in the United States Scientific organizations established in 1911

Current and former members

Publications

See also

References

External links