The Dominion Astrophysical Observatory, located on Observatory Hill, in

Saanich, British Columbia Saanich ( ) is a district municipality on Vancouver Island in British Columbia, within the Greater Victoria area. The population was 117,735 at the 2021 census, making it the most populous municipality in the Capital Regional District and V ...

, was completed in 1918 by the

Canadian government The government of Canada (french: gouvernement du Canada) is the body responsible for the federal administration of Canada. A constitutional monarchy, the Crown is the corporation sole, assuming distinct roles: the executive, as the ''Crown-in ...

. The Dominion architect responsible for the building was Edgar Lewis Horwood. The main instrument is the Plaskett

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observ ...

, proposed and designed by John S. Plaskett in 1910 with the support of the

International Union for Cooperation in Solar Research The International Union for Cooperation in Solar Research was an international organization dedicated to solar research between 1905 and 1913. It is one of the precursor organizations of the International Astronomical Union. Description The Unio ...

. The observatory has been designated a

national historic site of Canada National Historic Sites of Canada (french: Lieux historiques nationaux du Canada) are places that have been designated by the federal Minister of the Environment on the advice of the Historic Sites and Monuments Board of Canada (HSMBC), as being ...

, as it is a world-renowned facility where many discoveries about the nature of the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

were made, and it was one of the world’s main astrophysical research centres until the 1960s.

Public programs

The

Royal Astronomical Society of Canada Royal may refer to: People * Royal (name), a list of people with either the surname or given name * A member of a royal family Places United States * Royal, Arkansas, an unincorporated community * Royal, Illinois, a village * Royal, Iowa, ...

, Victoria Centre, which has a long association with the Dominion Astrophysical Observatory and public outreach dating back to 1914, holds free public "star parties" at the DAO on select summer Saturday evenings. These events include solar and nighttime viewing with RASC and DAO telescopes, presentations, lectures, and displays.

Centre of the Universe

The Centre of the Universe was the public interpretive centre for the observatory that was regularly open to the public between May and September. The centre featured interactive exhibits about astronomy, the work of the observatory and its parent organization, the

NRC Herzberg Institute of Astrophysics The NRC Herzberg Astronomy and Astrophysics Research Centre (NRC Herzberg, HAA) is the leading Canadian centre for astronomy and astrophysics. It is based in Victoria, British Columbia. The current Director-General, as of 2021, is Luc Simard. ...

. There were also tours of the telescope and programs in the planetarium and video theatre. The centre was closed by the federal government in August 2013, which stated financial issues as the reason. The Friends of the Dominion Astrophysical Observatory Society (FDAO) was formed in 2015 with a goal of reinstating the programs terminated when the Centre of the Universe was closed. In May 2016, the FDAO signed a licence to occupy for the Centre of the Universe with the

National Research Council National Research Council may refer to: * National Research Council (Canada), sponsoring research and development * National Research Council (Italy), scientific and technological research, Rome * National Research Council (United States), part of ...

Telescope construction

The building that houses the telescope was built by McAlpine-Robertson Company of Vancouver for a price of $75,000. Both the building and dome, made by

Warner & Swasey Company The Warner & Swasey Company was an American manufacturer of machine tools, instruments, and special machinery. It operated as an independent business firm, based in Cleveland, from its founding in 1880 until its acquisition in 1980. It was f ...

, are double walled. The glass mirror, in diameter and thick, weighs approximately and was made by the

Saint-Gobain Compagnie de Saint-Gobain S.A. () is a French multinational corporation, founded in 1665 in Paris and headquartered on the outskirts of Paris, at La Défense and in Courbevoie. Originally a mirror manufacturer, it now also produces a variety of ...

company in their Charleroi glass works in Antwerp, Belgium, and shipped only a week before the start of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. It was then ground in the United States at the John A. Brashear Co. (founded by astronomer and telescope pioneer John A. Brashear) in

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County. It is the most populous city in both Allegheny County and Western Pennsylvania, the second-most populous city in Pennsylva ...

. The mirror had to be reground twice, once due to a mysterious scratch and the second time due to a flaw in the grinding. This added two years to the completion time of the telescope, pushing the date back to 1918. The mirror was sent to Victoria by train, which arrived in Victoria six days later. The completed mirror was hauled up Little Saanich Mountain by horse and wagon. Images of the construction are available

Use

Following completion, Plaskett remained the head of the observatory until 1935. A spectrograph is fitted to the Cassegrain focus and an imaging

charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...

(CCD) is attached to the Newtonian focus. In 1962, a optical telescope was added to the observatory. The telescope, ordered in 1957, was made by

Grubb Parsons Sir Howard Grubb, Parsons and Co. Ltd. was a telescope manufacturer, more commonly known as Grubb Parsons. It was based in Newcastle upon Tyne, in England. They were a noted telescope maker throughout the 19th and 20th century, making telescope th ...

of Newcastle-upon-Tyne, England. Its

Coude focus A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternat ...

is used with a room-sized spectrograph. In 1995, the observatory was made the headquarters of the NRC

Herzberg Institute of Astrophysics The NRC Herzberg Astronomy and Astrophysics Research Centre (NRC Herzberg, HAA) is the leading Canadian centre for astronomy and astrophysics. It is based in Victoria, British Columbia. The current Director-General, as of 2021, is Luc Simard. ...

, which operates several Canadian telescopes, both optical and radio. The NRC collaborates with international partners such as the Canada-France-Hawaii Telescope. The telescopes are in constant use and are open for visitors year round. An interpretive centre called the Centre of the Universe was opened in 2002 but closed in 2013 due to budgetary reasons. The Centre of the Universe was reopened in 2014 through an arrangement with the a working group consisting of members of the public who came together in response to the closure, along with the Royal Astronomical Society of Canada's Victoria Centre, and Science Venture at the University of Victoria. Work on the non-profit charity Friends of the Dominion Astrophysical Observatory began in 2014 because of the desire of the National Research Council to deal with a single organization with respect to the Centre of the Universe, and it was formally constituted and registered in 2015. The Friends of the Dominion Astrophysical Observatory now runs the education programmes on-site and online. , the Dominion Astrophysical Observatory Director was Dr James De Francesco.

World-record status

Dominion Astrophysical Observatory, 1974

The Plaskett telescope was possibly planned to be the largest telescope in the world but delays meant it was completed and saw "first light" on May 6, 1918, six months after the

100-inch Hooker telescope The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observat ...

() at

Mount Wilson Observatory The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observat ...

. However, although the Hooker telescope achieved a first light on November 1, 1917, it was not really opened until 1918, which was also affected by delays especially from

. At this point most observatories still had 19th-century-era refractors of at most in aperture, as a shift to reflectors was still growing. It also surpassed the metal mirror

Leviathan of Parsonstown Leviathan of Parsonstown, or Rosse six-foot telescope, is a historic reflecting telescope of aperture, which was the largest telescope in the world from 1845 until the construction of the Hooker Telescope in California in 1917. The Rosse six-f ...

, built in 1845 but dismantled by the 1910s. The Plaskett telescope remained the second largest until the reflector at

David Dunlap Observatory The David Dunlap Observatory (DDO) is an astronomical observatory site in Richmond Hill, Ontario, Canada. Established in 1935, it was owned and operated by the University of Toronto until 2008. It was then acquired by the city of Richmond Hill, ...

in 1935 (also in Canada) debuted. Top 2 in 1918: The next largest were the

Harvard College Observatory The Harvard College Observatory (HCO) 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, United St ...

and the Mount Wilson 60-inch Hale.

References

External links

Official Site
Forecasts of observing conditions.

- scroll down the see the building
Paper by John S. Plaskett on the construction of the DAO
* Richard A. Jarrell
The Instrument was Instrumental: Plaskett's Telescope and Canadian Astronomy between the wars
* John S. Plaskett
History of Astronomy in British Columbia
*

Helen Sawyer Hogg Helen Battles Sawyer Hogg (August 1, 1905 – January 28, 1993) was an American-Canadian astronomer who pioneered research into globular clusters and variable stars. She was the first female president of several astronomical organizations and a ...

Memories of the Plaskett Era of the Dominion Astrophysical Observatory 1931–1934Photo of DAO, 1920, U. Wash Digital Collections
* (Book from 1923 about history and construction of the observatory) {{Authority control Astronomical observatories in Canada Buildings and structures in British Columbia Museums in British Columbia National Historic Sites in British Columbia Planetaria in Canada Saanich, British Columbia Science museums in Canada Defunct museums in Canada Tourist attractions in British Columbia