Dominion Astrophysical Observatory
Encyclopedia
The Dominion Astrophysical Observatory, located on Observatory Hill, in Saanich, British Columbia
, was completed in 1918 by the Canadian government. Proposed and designed by John S. Plaskett in 1910 with the support of the International Union for Cooperation in Solar Research, when the 72-inch aperture
telescope
was constructed, it was planned to be the largest telescope in the world but delays meant it saw first light after the Hooker 100-inch telescope.
The observatory has been designated a National Historic Site of Canada as it is a world-renowned facility where many discoveries about the nature of the Milky Way
were made, and it was one of the world’s main astrophysical research
centres until the 1960s.
The mirror weighs approximately 2000 kilograms and was made by the Saint-Gobain
company in their Charleroi glass works in Antwerp, Belgium
and shipped only a week before the start of World War I
. It was then ground in the United States
at the John A. Brashear company in Pittsburgh
. The mirror had to be reground twice, once due to a mysterious scratch and the 2nd time due to a flaw in the grinding. This added 2 years to the completion time of the telescope, pushing the date back to 1918. The completed mirror was hauled up Little Saanich Mountain by horse and wagon.
A spectrograph is fitted to the Cassegrain focus and an imaging CCD
is attached to the Newtonian focus.
In 1962, a 48" optical telescope was added to the observatory. The telescope, ordered in 1957, was made by Grubb Parsons of Newcastle-upon-Tyne, England
. Its Coude focus is used with a room sized specrograph.
In 1995, the observatory was made the headquarters of the NRC Herzberg Institute of Astrophysics
, which operates several Canadian telescopes, both optical and radio, as well as shares in international telescopes, such as the Canada-France-Hawaii Telescope
.
The telescopes are in constant use today and are open for visitors year round. An interpretive centre called the Centre of the Universe was opened in 2002.
As of July 2009, the current director was Dr James E Hesser.
in 1935 (also in Canada
) debuted.
Top 2 in 1918:
The next largest were the Harvard College Observatory
60 inch and the Mt. Wilson 60-inch Hale.
Saanich, British Columbia
The District of Saanich is a municipality on Vancouver Island in British Columbia. It is located north of the provincial capital, Victoria. It has a population of 108,265 people, making it the most populous municipality on Vancouver Island, and the seventh most populous in the province...
, was completed in 1918 by the Canadian government. Proposed and designed by John S. Plaskett in 1910 with the support of the International Union for Cooperation in Solar Research, when the 72-inch aperture
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...
telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
was constructed, it was planned to be the largest telescope in the world but delays meant it saw first light after the Hooker 100-inch telescope.
The observatory has been designated a National Historic Site of Canada as it is a world-renowned facility where many discoveries about the nature of the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
were made, and it was one of the world’s main astrophysical research
Astrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...
centres until the 1960s.
Centre of the Universe
Centre of the Universe is the public interpretive centre for the observatory that is regularly open to the public between May and September. The centre features interactive exhibits about astronomy, the work of the observatory and its parent organization, the NRC Herzberg Institute of Astrophysics. There are also tours of the telescope and programs in the planetarium and video theatre.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 and Swasey Co, are double walled.The mirror weighs approximately 2000 kilograms and was made by the Saint-Gobain
Saint-Gobain
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 construction and high-performance materials.The company has its head...
company in their Charleroi glass works in Antwerp, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
and shipped only a week before the start of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. It was then ground in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
at the John A. Brashear company in Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
. The mirror had to be reground twice, once due to a mysterious scratch and the 2nd time due to a flaw in the grinding. This added 2 years to the completion time of the telescope, pushing the date back to 1918. The completed mirror was hauled up Little Saanich Mountain by horse and wagon.
Use
Following completion, Plaskett remained the head of the observatory until 1935.A spectrograph is fitted to the Cassegrain focus and an imaging CCD
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
is attached to the Newtonian focus.
In 1962, a 48" optical telescope was added to the observatory. The telescope, ordered in 1957, was made by Grubb Parsons of Newcastle-upon-Tyne, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. Its Coude focus is used with a room sized specrograph.
In 1995, the observatory was made the headquarters of the NRC Herzberg Institute of Astrophysics
Herzberg Institute of Astrophysics
The NRC Herzberg Institute of Astrophysics is the leading Canadian centre for astronomy and astrophysics.Named for the Nobel laureate Gerhard Herzberg, it was formed in 1975 as part of the National Research Council of Canada in Ottawa, Ontario...
, which operates several Canadian telescopes, both optical and radio, as well as shares in international telescopes, such as the Canada-France-Hawaii Telescope
Canada-France-Hawaii Telescope
The Canada–France–Hawaii Telescope is located near the summit of Mauna Kea mountain on Hawaii's Big Island at an altitude of 4,204 meters , and is one of the observatories that comprise the Mauna Kea Observatory...
.
The telescopes are in constant use today and are open for visitors year round. An interpretive centre called the Centre of the Universe was opened in 2002.
As of July 2009, the current director was Dr James E Hesser.
Plaskett telescope contemporaries on commissioning
The Plaskett missed becoming the largest telescope in the World, but remained the second largest until the 74 inch (188 cm) reflector at David Dunlap ObservatoryDavid Dunlap Observatory
The David Dunlap Observatory is a large astronomical observatory site once owned by the University of Toronto, located just north of the city in Richmond Hill, Ontario within a estate. Its primary instrument is a 74-inch reflector telescope, at one time the second largest telescope in the world,...
in 1935 (also in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
) debuted.
Top 2 in 1918:
| # | Name / Observatory |
Image | Aperture | Altitude | First Light |
Special advocate |
|---|---|---|---|---|---|---|
| 1 | Hooker Telescope Mount Wilson Obs. Mount Wilson Observatory The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,715 foot peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles... |
 |
100 inch 254 cm |
1742 m (5715 ft) |
1917 | George Ellery Hale George Ellery Hale George Ellery Hale was an American solar astronomer.-Biography:Hale was born in Chicago, Illinois. He was educated at MIT, at the Observatory of Harvard College, , and at Berlin . As an undergraduate at MIT, he is known for inventing the spectroheliograph, with which he made his discovery of... Andrew Carnegie Andrew Carnegie Andrew Carnegie was a Scottish-American industrialist, businessman, and entrepreneur who led the enormous expansion of the American steel industry in the late 19th century... |
| 2 | Plaskett telescope Dominion Astrophysical Obs. |
 |
72 inch 182 cm |
230 m (755 ft) |
1918 | John S. Plaskett |
The next largest were 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...
60 inch and the Mt. Wilson 60-inch Hale.
See also
- NRC Herzberg Institute of AstrophysicsHerzberg Institute of AstrophysicsThe NRC Herzberg Institute of Astrophysics is the leading Canadian centre for astronomy and astrophysics.Named for the Nobel laureate Gerhard Herzberg, it was formed in 1975 as part of the National Research Council of Canada in Ottawa, Ontario...
- Dominion Radio Astrophysical ObservatoryDominion Radio Astrophysical ObservatoryThe Dominion Radio Astrophysical Observatory is a research facility founded in 1960 and located south-west of Okanagan Falls, British Columbia, Canada. The site houses three instruments – an interferometric radio telescope, a 26-m single-dish antenna, and a solar flux monitor – and...
- List of largest optical reflecting telescopes
External links
- Dominion Astrophysical Observatory
- Centre of the Universe
- Dominion Astrophysical Observatory Clear Sky Clock Forecasts of observing conditions.
- District of Saanich Significant Buildings - scroll down the see the building
- Paper by John S. Plaskett on the construction of the DAO
- Paper about 48" telescope
- 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 HoggHelen Sawyer HoggHelen Battles Sawyer Hogg, CC was a prolific astronomer noted for her research into globular clusters...
, Memories of the Plaskett Era of the Dominion Astrophysical Observatory 1931–1934 - Photo of DAO, 1920, U. Wash Digital Collections