IAU Circular
Encyclopedia
The International Astronomical Union
Circulars (IAUCs) are notices that give information about astronomical phenomena. IAUCs are issued by the IAU's Central Bureau for Astronomical Telegrams
(CBAT) at irregular intervals for the discovery and follow-up information regarding such objects as planetary satellites, nova
e, supernova
e, and comet
s. The first series of IAUCs was published at Uccle
during 1920–1922 when the IAU's first CBAT was located there; the first IAUC published in the present (second) series was published in 1922 at Copenhagen Observatory in Denmark after the transfer of the CBAT from Uccle to Copenhagen. At the end of 1964, the CBAT moved from Copenhagen
to the Smithsonian Astrophysical Observatory
in Cambridge, Massachusetts
, where it has remained to this day, on the grounds of the Harvard College Observatory
. HCO had maintained a Central Bureau for the western hemisphere from 1883 until the end of 1964, when its staff took on the IAU's CBAT; HCO had published its own Announcement Cards that paralleled/complemented the IAUCs from 1926 until the end of 1964, but the Announcement Cards ceased publication when the IAUCs began to be issued from the same building.
The IAUCs are delivered via the United States Postal Service
, e-mail, and through the Central Bureau for Astronomical Telegrams
/Minor Planet Center
(CBAT/MPC) Computer Service. Most of the announcement circulars published at Cambridge, Copenhagen, and Uccle from 1895 to the present day are available for viewing via the CBAT website.
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
Circulars (IAUCs) are notices that give information about astronomical phenomena. IAUCs are issued by the IAU's Central Bureau for Astronomical Telegrams
Central Bureau for Astronomical Telegrams
The Central Bureau for Astronomical Telegrams is the official international clearing house for information relating to transient astronomical events....
(CBAT) at irregular intervals for the discovery and follow-up information regarding such objects as planetary satellites, nova
Nova
A nova is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the surface of a white dwarf star, which ignites and starts nuclear fusion in a runaway manner...
e, supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
e, and comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s. The first series of IAUCs was published at Uccle
Uccle
Uccle or Ukkel is one of the nineteen municipalities located in the Brussels-Capital Region of Belgium.Uccle is known for its well-to-do areas, its green spots and its high rental rates.-History:...
during 1920–1922 when the IAU's first CBAT was located there; the first IAUC published in the present (second) series was published in 1922 at Copenhagen Observatory in Denmark after the transfer of the CBAT from Uccle to Copenhagen. At the end of 1964, the CBAT moved from Copenhagen
Copenhagen
Copenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...
to the Smithsonian Astrophysical Observatory
Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory to form the Harvard-Smithsonian Center for Astrophysics .-History:The SAO was founded in 1890 by...
in Cambridge, Massachusetts
Cambridge, Massachusetts
Cambridge is a city in Middlesex County, Massachusetts, United States, in the Greater Boston area. It was named in honor of the University of Cambridge in England, an important center of the Puritan theology embraced by the town's founders. Cambridge is home to two of the world's most prominent...
, where it has remained to this day, on the grounds of the Harvard College Observatory
Harvard College Observatory
The Harvard College Observatory is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, USA, and was founded in 1839...
. HCO had maintained a Central Bureau for the western hemisphere from 1883 until the end of 1964, when its staff took on the IAU's CBAT; HCO had published its own Announcement Cards that paralleled/complemented the IAUCs from 1926 until the end of 1964, but the Announcement Cards ceased publication when the IAUCs began to be issued from the same building.
The IAUCs are delivered via the United States Postal Service
United States Postal Service
The United States Postal Service is an independent agency of the United States government responsible for providing postal service in the United States...
, e-mail, and through the Central Bureau for Astronomical Telegrams
Central Bureau for Astronomical Telegrams
The Central Bureau for Astronomical Telegrams is the official international clearing house for information relating to transient astronomical events....
/Minor Planet Center
Minor Planet Center
The Minor Planet Center operates at the Smithsonian Astrophysical Observatory , which is part of the Center for Astrophysics along with the Harvard College Observatory ....
(CBAT/MPC) Computer Service. Most of the announcement circulars published at Cambridge, Copenhagen, and Uccle from 1895 to the present day are available for viewing via the CBAT website.