David Dunlap Observatory
Encyclopedia
The David Dunlap Observatory (DDO) 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 189 acres (76.5 ha) estate. Its primary instrument is a 74-inch (1.88 m) reflector telescope
, at one time the second largest telescope in the world, and still the largest in Canada. Several other telescopes are also located at the site, which formerly included a small radio telescope
as well. Located on a hill, yet still relatively close to sea level
at 730 ft. (238 m) above sea level, and now surrounded by subdivisions
, optical astronomy ability has been reduced as compared to other remote observatory sites around the world. Nevertheless, the DDO can still be used for spectral astronomy and is the site of a number of important studies, including pioneering measurements of the distance to globular cluster
s, providing the first direct evidence that Cygnus X-1
was a black hole
, and the discovery that Polaris
was stabilizing and appeared to be "falling out" of the Cepheid variable
category.
. Chant had not shown an early interest in astronomy, but while attending University College, University of Toronto
he became interested in mathematics
and physics
, eventually joining the University as a lecturer in physics in 1892. Over the next several years he worked as a schoolteacher and civil servant. During a later leave of absence he earned his PhD from Harvard University
and did postdoctoral work in Germany.
Chant joined the Astronomical and Physical Society of Toronto in December 1892; it was eventually renamed the Royal Astronomical Society of Canada
in 1902. Chant became president of the Society, serving between 1904 and 1907. Throughout the 1890s, Chant was concerned about how little the University did for astronomy, and in 1904 he proposed adding several undergraduate courses for fourth-year students, and six such courses were added to the 1905 calendar.
With courses now officially on the books, Chant started looking for a proper telescope. Previously the University had hosted the Toronto Magnetic and Meteorological Observatory
, which had been run by the Meteorological Office of the Ministry of Marine and Fisheries
. The Observatory had contained the high-quality 6 inches (152.4 mm) Cooke Refractor, but the Observatory was now surrounded by new University buildings, rendering it useless for astronomy. The Meteorological Office had already decided to abandon the site and turn the building over to the University, but they were taking the telescope with them to their new location on Bloor Street
. Even if the University had been able to secure time on the instrument, which was highly likely, it was at this time quite a small instrument in comparison to those being built around the world.
The same problem of encroachment that had led to the Observatory falling into disuse led Chant to conclude that there was no suitable location on the University grounds for a new observatory, and he started looking for off-campus sites. While looking, he started getting quotes for a new instrument from Warner & Swasey
in Cleveland, Ohio
, who had provided the mount for the recently opened Dominion Observatory
in Ottawa
. In 1910 Chant finally found the perfect location, a 10 acres (40,468.6 m²) plot of land located near what is today Bathurst Street and St. Clair Avenue
. The land had originally been set aside by the city for the Isolation Hospital, but this was never constructed and it now lay empty. Chant convinced the City to become involved in the Royal Astronomical Observatory, but the outbreak of World War I
put the project on hold, and in 1919 it was cancelled outright.
, which had recently been visible in Canada. One of the attendees was mining executive David Dunlap, who was bitten by the astronomy bug as a result of the lecture, and expressed an interest in Chant's efforts to build a large observatory. Before making any firm financial commitment, however, Dunlap died in October 1924 at age 61. Chant approached his widow, Jessie Dunlap, in late 1926 with the idea of erecting an observatory as a monument to her husband. Mrs. Dunlap promised to "keep it in [her] heart for consideration, for it appeals to me tremendously."
By this point the original site was well within the rapidly growing city's lit areas, and no longer suitable for astronomy. A site much further from the city was needed, to ensure it too would not be crowded out. The first site studied was outside Aurora, Ontario
, but it was decided that it was too far from the university for casual travel. Another site near Hogg's Hollow was also studied, but was not easily accessible. The eventual site was selected while Chant was studying topographical maps with fellow astronomer Reynold Young, finding a suitable spot north of the city. When Chant took Dunlap to see the site for the first time, she stated "this is the place!" and authorized its purchase for C$
28,000.
Chant immediately started ordering a telescope, selecting a 74 inches (1.9 m) instrument from Grubb, Parsons and Company
in England. This would make it the second largest telescope in the world, second only to the 100 inches (2.5 m) instrument at Mount Wilson Observatory
. It was, however, only slightly larger than the one that had recently gone into service for the Dominion Astrophysical Observatory
in British Columbia
, at 72 inches (1.8 m). The observatory building itself started construction, and the eighty-ton sixty-one-foot (18.6 m) copper dome arrived in 1933. The administration building, a few hundred feet from the main observatory, also started construction. The 76 inches (1.9 m) mirror blank (the two outermost inches (5 cm) of the mirror are not used) was supplied by Corning Incorporated and cast in Pyrex
from a batch of glass that Corning also used to produce the 200 inches (5.1 m) mirror for Palomar Observatory
. Chant and Mrs. Dunlap attended the pouring of the mirror at the factory in Corning, NY in June 1933. The mirror was annealed, then shipped to Grubb-Parsons in England for polishing. The telescope was completed in time for the finished mirror's return in May 1935.
The official opening was on 31 May 1935, Chant's 70th birthday. The opening ceremony was attended by notables such as Sir Frank Dyson
, former Astronomer Royal
, and former Prime Minister William Lyon Mackenzie King
, who praised the Observatory as "a gift to science all over the world." Chant retired the same day and moved into Observatory House, the original pre-Confederation
farmhouse
just to the south of the administration buildings, where he spent his remaining years. In May, 1939 the train carrying King George VI and Queen Elizabeth, the Queen Mother on their cross-Canada tour paused on the railway below the observatory, the largest telescope in the commonwealth.
Grubb-Parsons built four more 1.88-metre telescopes with similarities to the instrument in Richmond Hill: for Radcliffe Observatory
near Pretoria, Mount Stromlo Observatory
in Australia, Helwan Observatory in Egypt, and an observatory in Okayama Prefecture
in Japan. The South African instrument was disassembled and moved to Sutherland, Northern Cape
in the 1970s because of light pollution. The original telescope mirror at Helwan was replaced by Zeiss in 1997, and the telescope at Mount Stromlo was destroyed by fire in 2003. A 1.93-metre Grubb-Parsons telescope at Haute-Provence Observatory
with a higher-resolution spectrograph was used to discover an extrasolar planet orbiting the star 51 Pegasi
in 1995.
The three smaller domes on the top of the DDO administration building are used for smaller instruments. Soon after the observatory opened in 1935, a 50 cm Cassegrain reflector
telescope was installed in the southern dome. The 6 inches (152.4 mm) Cooke Refractor had been out of use since the Meteorological Office had given it to Hart House, but it was little used and was moved into the northern dome in 1951 to be used by undergraduates. Much later, in 1965, another similar 60 cm Cassegrain was added to the central dome.
, who was joined at the DDO by his wife Helen Sawyer Hogg
. After her husband's death, Helen continued at the observatory, surveying globular clusters to gauge their distance. Her weekly 'With the Stars' column in the Toronto Star
was published from 1951 to 1981. In 1959 and 1966 staff astronomer Sidney van den Bergh
composed a database of dwarf galaxies known as the David Dunlap Observatory Catalogue.
In collaboration with the Department of Electrical Engineering, Dr. MacRae established a radio astronomy observatory on the observatory grounds in 1956. The DDO work led to the precise determination of the absolute flux density of Cassiopeia A
at 320 MHz, a radiometric standard as important today as it was when it was reported in 1963. The DDO also built an 18 m radio telescope
in Algonquin Park in northern Ontario, co-locating it at the site of the larger Algonquin Radio Observatory
. This instrument was actively used until 1991, when budget cuts led to it being abandoned. It was later used by a private group as part of a SETI
project, Project TARGET, and has recently been moved to a site outside Shelburne, Ontario
.
In 1960 observatory operations formed the narrative framework of the NFB short film Universe. The film was nominated for the 33rd Academy Awards
in the category of best documentary, short subject in 1961. Universe was shown at the 1964 New York World's Fair
where it was seen by Stanley Kubrick and Arthur C. Clarke, who were starting work on the film that eventually became 2001: A Space Odyssey
. Universe featured future DDO director Donald MacRae
and was narrated by Stanley Jackson.
University of Toronto Professor Tom Bolton
was hired at the DDO in 1970. In 1971 he used data from the Uhuru
X-ray observatory, and Naval Research Laboratory sounding rockets launched from White Sands Missile Range
to find the optical companion star to the X-ray source Cygnus X-1. Those X-ray telescopes had a certain degree of accuracy, but follow-up optical-wavelength studies of possible companions were required to eliminate a shortlist of many stars in the same area of sky. Bolton observed the star HDE 226868 independently of the work by Louise Webster and Paul Murdin, at the Royal Greenwich Observatory, who could not prove that star was Cygnus X-1's optical companion. The high dispersion of the 74 inches (1.9 m) telescope's spectrograph, combined with the 74 inches (1.9 m) aperture was adequate to prove the star was the source of the X-ray emissions and that its behaviour was inconsistent with a normal eclipsing star.
in 1984.
The main reflector at the DDO remained a major instrument into the 1960s, but in the end even the "remote" location Chant had selected was being encroached on by urban sprawl
. Although some consideration was given to moving the telescope to a new site, in the end it was decided the funds would be better spent on a smaller instrument in a much better location. This led to the building of a 60 cm instrument at Las Campanas
in Chile
in 1971, creating the University of Toronto Southern Observatory
(UTSO). It was at this location that University of Toronto astronomer Ian Shelton
discovered Supernova 1987A, the first supernova visible to the naked eye in more than 350 years. The UTSO was later closed in 1997 to re-allocate funds to a share of the Gemini Observatory
, and the 60 cm telescope was moved to El Leoncito in Argentina, where the University has a 25% share in observation time.
While University operations continued at the DDO, international observers used about 50% of observing time there. In 2007, the telescope was used by astronomers from Ege University
in Turkey, the Slovak Academy of Sciences
in Slovakia, University of Valencia in Spain, Tartu Observatory
in Estonia, and the University of Wrocław and Pedagogical University of Cracow
in Poland.
, the Canada-France-Hawaii Telescope
, the Atacama Large Millimeter Array
and the Gemini Observatory
. None of these telescopes are located in Canada. After the UTSO was closed, in 1998 the Canadian Astronomical Society
, a society of university astronomers, published a long range plan emphasizing the study of the origins of structure in the universe, a task well-suited to cutting-edge telescopes but ill-suited to the DDO. The long range plan suggested the future of observatories such as the DDO lay in public outreach programs and training. In 2005 Canadian universities joined a partnership to build the Thirty Meter Telescope
, expected to cost >$1 billion.
In September 2007, the University stated it was planning on selling the DDO property owing to light pollution
. The University's governing council voted on the issue during the week of 1 November 2007, and agreed to sell the site to the highest bidder. The 75 ha
of land in the midst of a huge subdivision area was expected to fetch $100 million some of which the University planned to use to found a Dunlap Institute to continue astronomical research. The sale was called a "cash grab" by Richmond Hill Mayor David Barrow.
For the purposes of the sale, the land was partitioned into a 71 ha
Parcel A and a 5 ha Parcel B, upon which sits the Elvis Stojko Hockey Arena and also a park with a 200-metre-wide solar system model
. The arena is leased by the Town, now from the new owner, until 2015. At the end of June 2008, the University completed the sale of both parcels of the property to Corsica Development Inc., a subsidiary of Metrus Development Inc. for $70 million, a lower price than expected. Observatory staff were laid off and faculty reassigned to the downtown St. George campus. The Town of Richmond Hill planned a hearing with the Conservation Review Board of Ontario to argue for protection of the western 48% of the property including the observatory buildings under the Ontario Heritage Act
; at the hearing, the Richmond Hill Naturalists argued for 100% designation of the property, all the buildings and their contents, and the Observatory Hill Homeowners Association argued for the protection of the heritage woodlots and arboretums. Corsica Development Inc. was also be represented before the CRB. Preliminary hearings took place on September 3 and October 15, 2008. Corsica Development Inc. is administered by Metrus in conjunction with The Conservatory Group and Marel Contracting.
The Conservation Review Board hearing to determine the extent of the Cultural Heritage Landscape designation to be afforded to the Dunlap site took place in Richmond Hill between January 15 to 23, 2009, and the Board recommendation was published on June 4. The Board recommended preservation of the observatory buildings and up to 80% of the property as a cultural heritage landscape. On September 29, 2009 Richmond Hill Town Council voted unanimously in favour of the designating by-law. The Town proceeded with a number of public meetings and reports in late 2009 to craft guidelines for the conservation, planning and design of the property. Corsica Development Inc. undertook an archaeological survey of the property. On April 15, 2010 stemming from an incident on the property in November 2009, Corsica Development Inc. pled guilty in York Region court to 17 counts of cutting a tree without a permit and was issued a fine of $44,880. The company also planted 100 new trees on the property as part of the judgment.
In January 2009, Corsica published the website observatoryhill.ca describing the property, stating, "[We] are in the process of looking for an astronomy club to occupy the observatory and welcome proposals for consideration." On April 22, 2009 Corsica and the Royal Astronomical Society of Canada, Toronto Centre announced an agreement allowing the RASC to provide public education and outreach programs at the observatory, and to operate the 1.88m telescope. On June 14, the RASC Toronto Centre published the website www.theddo.ca to make tickets available for public astronomy nights at the observatory starting on July 18. Astronomy events at the observatory continued through the remainder of 2009 and 2010, such as Perseid meteor shower events both years that drew high attendance and media coverage. These new operations continued in 2011, combined with opportunities such as use of the observatory for a location shoot of the SyFy television series Warehouse 13
.
the University of Toronto started several initiatives connected with the foundation of the Dunlap Institute. The University's Department of Astronomy and Astrophysics, which already had close ties with the Canadian Institute for Theoretical Astrophysics
(CITA) announced it was seeking a director for the Dunlap Institute. At the same time Ivan Semeniuk, a well-known Canadian science journalist, joined the Dunlap Institute as Journalist-in-Residence. Dr. Ray Jayawardhana
, Canada Research Chair in Observational Astrophysics, announced a series of high-impact advertisements on subways and other vehicles of the Toronto Transit Commission
linking to the Institute's World Wide Web presence at www.coolcosmos.net. The Dunlap Institute, along with CITA and the Department of Astronomy and Astrophysics co-hosted the 2009 annual meeting of CASCA in May, including the annual Helen Sawyer Hogg Lecture sponsored jointly with the Royal Astronomical Society of Canada. The lecture was given by Lawrence M. Krauss
. In July 2010 James R. Graham
was announced as the new Dunlap Institute director.
Three largest telescopes in 1935:
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
observatory
Observatory
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...
site once owned by the University of Toronto
University of Toronto
The University of Toronto is a public research university in Toronto, Ontario, Canada, situated on the grounds that surround Queen's Park. It was founded by royal charter in 1827 as King's College, the first institution of higher learning in Upper Canada...
, located just north of the city in Richmond Hill, Ontario
Richmond Hill, Ontario
Richmond Hill is a town located in Southern Ontario, Canada in the central portion of York Region, Ontario. It is part of the Greater Toronto Area, being located about halfway between Toronto and Lake Simcoe...
within a 189 acres (76.5 ha) estate. Its primary instrument is a 74-inch (1.88 m) reflector telescope
Reflecting telescope
A reflecting telescope is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the refracting telescope which, at that time, was a design that suffered from...
, at one time the second largest telescope in the world, and still the largest in Canada. Several other telescopes are also located at the site, which formerly included a small radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
as well. Located on a hill, yet still relatively close to sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
at 730 ft. (238 m) above sea level, and now surrounded by subdivisions
Subdivision (land)
Subdivision is the act of dividing land into pieces that are easier to sell or otherwise develop, usually via a plat. The former single piece as a whole is then known in the United States as a subdivision...
, optical astronomy ability has been reduced as compared to other remote observatory sites around the world. Nevertheless, the DDO can still be used for spectral astronomy and is the site of a number of important studies, including pioneering measurements of the distance to globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
s, providing the first direct evidence that Cygnus X-1
Cygnus X-1
Cygnus X-1 is a well-known galactic X-ray source in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 2.3 Wm−2Hz−1...
was a black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
, and the discovery that Polaris
Polaris
Polaris |Alpha]] Ursae Minoris, commonly North Star or Pole Star, also Lodestar) is the brightest star in the constellation Ursa Minor. It is very close to the north celestial pole, making it the current northern pole star....
was stabilizing and appeared to be "falling out" of the Cepheid variable
Cepheid variable
A Cepheid is a member of a class of very luminous variable stars. The strong direct relationship between a Cepheid variable's luminosity and pulsation period, secures for Cepheids their status as important standard candles for establishing the Galactic and extragalactic distance scales.Cepheid...
category.
Genesis
The DDO owes its existence almost entirely to the efforts of one man, Clarence ChantClarence Chant
Clarence Augustus Chant was a Canadian astronomer and physicist.He was born in Hagermans Corners, Ontario to Christopher Chant and Elizabeth Croft. In 1882 he attended Markham High School, where he demonstrated a mathematical ability. After graduation he attended St. Catherines Collegiate...
. Chant had not shown an early interest in astronomy, but while attending University College, University of Toronto
University College, University of Toronto
University College is a constituent college of the University of Toronto, created in 1853 specifically as an institution of higher learning free of religious affiliation. It was the founding member of the university's modern collegiate system, and its secularism contrasted with contemporary...
he became interested in mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
and physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, eventually joining the University as a lecturer in physics in 1892. Over the next several years he worked as a schoolteacher and civil servant. During a later leave of absence he earned his PhD from Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
and did postdoctoral work in Germany.
Chant joined the Astronomical and Physical Society of Toronto in December 1892; it was eventually renamed the Royal Astronomical Society of Canada
Royal Astronomical Society of Canada
The Royal Astronomical Society of Canada is a national, non-profit, charitable organization devoted to the advancement of astronomy and related sciences. At present, there are 29 local branches of the Society, called centres, located in towns and cities across the country from St. John's,...
in 1902. Chant became president of the Society, serving between 1904 and 1907. Throughout the 1890s, Chant was concerned about how little the University did for astronomy, and in 1904 he proposed adding several undergraduate courses for fourth-year students, and six such courses were added to the 1905 calendar.
With courses now officially on the books, Chant started looking for a proper telescope. Previously the University had hosted the Toronto Magnetic and Meteorological Observatory
Toronto Magnetic and Meteorological Observatory
The Toronto Magnetic and Meteorological Observatory is a historical observatory located on the grounds of the University of Toronto, in Toronto, Ontario, Canada. The original building was constructed in 1840 as part of a worldwide research project run by Edward Sabine to determine the cause of...
, which had been run by the Meteorological Office of the Ministry of Marine and Fisheries
Fisheries and Oceans Canada
Fisheries and Oceans Canada, frequently referred to as DFO , is the department within the government of Canada that is responsible for developing and implementing policies and programs in support of Canada's economic, ecological and scientific interests in oceans and inland waters...
. The Observatory had contained the high-quality 6 inches (152.4 mm) Cooke Refractor, but the Observatory was now surrounded by new University buildings, rendering it useless for astronomy. The Meteorological Office had already decided to abandon the site and turn the building over to the University, but they were taking the telescope with them to their new location on Bloor Street
Bloor Street
Bloor Street is a major east–west residential and commercial thoroughfare in Toronto, in the Canadian province of Ontario. Bloor Street runs from the Prince Edward Viaduct westward into Mississauga, where it ends at Central Parkway. East of the viaduct, Danforth Avenue continues along the same...
. Even if the University had been able to secure time on the instrument, which was highly likely, it was at this time quite a small instrument in comparison to those being built around the world.
The same problem of encroachment that had led to the Observatory falling into disuse led Chant to conclude that there was no suitable location on the University grounds for a new observatory, and he started looking for off-campus sites. While looking, he started getting quotes for a new instrument from Warner & Swasey
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...
in Cleveland, Ohio
Cleveland, Ohio
Cleveland is a city in the U.S. state of Ohio and is the county seat of Cuyahoga County, the most populous county in the state. The city is located in northeastern Ohio on the southern shore of Lake Erie, approximately west of the Pennsylvania border...
, who had provided the mount for the recently opened Dominion Observatory
Dominion Observatory
The Dominion Observatory was an astronomical observatory in Ottawa, Canada that operated from 1902 to 1970. The Observatory was also an institution within the Canadian Federal Government. The observatory grew out of the Department of the Interior's need for the precise coordinates and timekeeping...
in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
. In 1910 Chant finally found the perfect location, a 10 acres (40,468.6 m²) plot of land located near what is today Bathurst Street and St. Clair Avenue
St. Clair Avenue
St. Clair Avenue is a major east-west street in Toronto, Ontario, Canada. It was laid out in the late 18th century by the British as a concession road , north of Bloor Street and north of Queen Street....
. The land had originally been set aside by the city for the Isolation Hospital, but this was never constructed and it now lay empty. Chant convinced the City to become involved in the Royal Astronomical Observatory, but the outbreak 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...
put the project on hold, and in 1919 it was cancelled outright.
Dunlap involvement
Chant then turned to the local business community in hopes of finding funding. Similar collaborations had been very successful in the United States, but Chant found an entirely different reception in Canada and nothing seemed forthcoming. His fortunes changed in 1921 when Chant delivered a public lecture on Comet 7P/Pons-Winnecke7P/Pons-Winnecke
7P/Pons–Winnecke is a periodic comet in our solar system.Jean Louis Pons originally discovered the comet on June 12, 1819, it was later rediscovered by Friedrich August Theodor Winnecke on March 9, 1858. It is believed to be the parent body of the June Bootids of late June.7P has an orbital...
, which had recently been visible in Canada. One of the attendees was mining executive David Dunlap, who was bitten by the astronomy bug as a result of the lecture, and expressed an interest in Chant's efforts to build a large observatory. Before making any firm financial commitment, however, Dunlap died in October 1924 at age 61. Chant approached his widow, Jessie Dunlap, in late 1926 with the idea of erecting an observatory as a monument to her husband. Mrs. Dunlap promised to "keep it in [her] heart for consideration, for it appeals to me tremendously."
By this point the original site was well within the rapidly growing city's lit areas, and no longer suitable for astronomy. A site much further from the city was needed, to ensure it too would not be crowded out. The first site studied was outside Aurora, Ontario
Aurora, Ontario
Aurora is an affluent town in York Region, approximately 20 km north of Toronto. It is partially situated on the Oak Ridges Moraine, and is a part of the Greater Toronto Area and Golden Horseshoe of Southern Ontario.Many Aurora residents commute to Toronto and surrounding communities.In the...
, but it was decided that it was too far from the university for casual travel. Another site near Hogg's Hollow was also studied, but was not easily accessible. The eventual site was selected while Chant was studying topographical maps with fellow astronomer Reynold Young, finding a suitable spot north of the city. When Chant took Dunlap to see the site for the first time, she stated "this is the place!" and authorized its purchase for C$
Canadian dollar
The Canadian dollar is the currency of Canada. As of 2007, the Canadian dollar is the 7th most traded currency in the world. It is abbreviated with the dollar sign $, or C$ to distinguish it from other dollar-denominated currencies...
28,000.
Construction
Sir Howard Grubb, Parsons and Co. Ltd.
Sir Howard Grubb, Parsons and Co. Ltd. was a telescope manufacturer, more commonly known as Grubb Parsons based in Newcastle upon Tyne.-History:...
in England. This would make it the second largest telescope in the world, second only to the 100 inches (2.5 m) instrument at Mount Wilson Observatory
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...
. It was, however, only slightly larger than the one that had recently gone into service for the Dominion Astrophysical Observatory
Dominion Astrophysical Observatory
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...
in British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, at 72 inches (1.8 m). The observatory building itself started construction, and the eighty-ton sixty-one-foot (18.6 m) copper dome arrived in 1933. The administration building, a few hundred feet from the main observatory, also started construction. The 76 inches (1.9 m) mirror blank (the two outermost inches (5 cm) of the mirror are not used) was supplied by Corning Incorporated and cast in Pyrex
Pyrex
Pyrex is a brand name for glassware, introduced by Corning Incorporated in 1915.Originally, Pyrex was made from borosilicate glass. In the 1940s the composition was changed for some products to tempered soda-lime glass, which is the most common form of glass used in glass bakeware in the US and has...
from a batch of glass that Corning also used to produce the 200 inches (5.1 m) mirror for Palomar Observatory
Palomar Observatory
Palomar Observatory is a privately owned observatory located in San Diego County, California, southeast of Pasadena's Mount Wilson Observatory, in the Palomar Mountain Range. At approximately elevation, it is owned and operated by the California Institute of Technology...
. Chant and Mrs. Dunlap attended the pouring of the mirror at the factory in Corning, NY in June 1933. The mirror was annealed, then shipped to Grubb-Parsons in England for polishing. The telescope was completed in time for the finished mirror's return in May 1935.
The official opening was on 31 May 1935, Chant's 70th birthday. The opening ceremony was attended by notables such as Sir Frank Dyson
Frank Watson Dyson
Sir Frank Watson Dyson, KBE, FRS was an English astronomer and Astronomer Royal who is remembered today largely for introducing time signals from Greenwich, England, and for the role he played in testing Einstein's theory of general relativity.- Biography :Dyson was born in Measham, near...
, former Astronomer Royal
Astronomer Royal
Astronomer Royal is a senior post in the Royal Household of the Sovereign of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the second is the Astronomer Royal for Scotland dating from 1834....
, and former Prime Minister William Lyon Mackenzie King
William Lyon Mackenzie King
William Lyon Mackenzie King, PC, OM, CMG was the dominant Canadian political leader from the 1920s through the 1940s. He served as the tenth Prime Minister of Canada from December 29, 1921 to June 28, 1926; from September 25, 1926 to August 7, 1930; and from October 23, 1935 to November 15, 1948...
, who praised the Observatory as "a gift to science all over the world." Chant retired the same day and moved into Observatory House, the original pre-Confederation
Canadian Confederation
Canadian Confederation was the process by which the federal Dominion of Canada was formed on July 1, 1867. On that day, three British colonies were formed into four Canadian provinces...
farmhouse
Farmhouse
Farmhouse is a general term for the main house of a farm. It is a type of building or house which serves a residential purpose in a rural or agricultural setting. Most often, the surrounding environment will be a farm. Many farm houses are shaped like a T...
just to the south of the administration buildings, where he spent his remaining years. In May, 1939 the train carrying King George VI and Queen Elizabeth, the Queen Mother on their cross-Canada tour paused on the railway below the observatory, the largest telescope in the commonwealth.
Grubb-Parsons built four more 1.88-metre telescopes with similarities to the instrument in Richmond Hill: for Radcliffe Observatory
Radcliffe Observatory
Radcliffe Observatory was the astronomical observatory of Oxford University from 1773 until 1934, when the Radcliffe Trustees sold it and erected a new observatory in Pretoria, South Africa. It is a grade I listed building.- History :...
near Pretoria, Mount Stromlo Observatory
Mount Stromlo Observatory
Mount Stromlo Observatory located just outside of Canberra, Australia, is part of the Research School of Astronomy and Astrophysics at the Australian National University .-History:...
in Australia, Helwan Observatory in Egypt, and an observatory in Okayama Prefecture
Okayama Prefecture
is a prefecture of Japan located in the Chūgoku region on Honshū island. The capital is the city of Okayama.- History :During the Meiji Restoration, the area of Okayama Prefecture was known as Bitchū Province, Bizen Province and Mimasaka Province.- Geography :...
in Japan. The South African instrument was disassembled and moved to Sutherland, Northern Cape
Sutherland, Northern Cape
- External links :* * *...
in the 1970s because of light pollution. The original telescope mirror at Helwan was replaced by Zeiss in 1997, and the telescope at Mount Stromlo was destroyed by fire in 2003. A 1.93-metre Grubb-Parsons telescope at Haute-Provence Observatory
Haute-Provence Observatory
The Observatoire de Haute-Provence was established in 1937 as a national facility for French astronomers. Astronomical observations began in 1943 using the 1.20 m telescope, and the first research papers based on observations made at the observatory were published in 1944...
with a higher-resolution spectrograph was used to discover an extrasolar planet orbiting the star 51 Pegasi
51 Pegasi
51 Pegasi is a Sun-like star located 15.6 parsecs from Earth in the constellation Pegasus...
in 1995.
The three smaller domes on the top of the DDO administration building are used for smaller instruments. Soon after the observatory opened in 1935, a 50 cm Cassegrain reflector
Cassegrain reflector
The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas....
telescope was installed in the southern dome. The 6 inches (152.4 mm) Cooke Refractor had been out of use since the Meteorological Office had given it to Hart House, but it was little used and was moved into the northern dome in 1951 to be used by undergraduates. Much later, in 1965, another similar 60 cm Cassegrain was added to the central dome.
Operations
From 1946 to 1951 the observatory director was Frank Scott HoggFrank Scott Hogg
Frank Scott Hogg was born to Dr. James Scott Hogg and Ida Barberon in Preston, Ontario.After earning and undergraduate degree from the University of Toronto, Hogg received the second doctorate in astronomy awarded at Harvard University in 1929 where he pioneered in the study of spectrophotometry...
, who was joined at the DDO by his wife Helen Sawyer Hogg
Helen Sawyer Hogg
Helen Battles Sawyer Hogg, CC was a prolific astronomer noted for her research into globular clusters...
. After her husband's death, Helen continued at the observatory, surveying globular clusters to gauge their distance. Her weekly 'With the Stars' column in the Toronto Star
Toronto Star
The Toronto Star is Canada's highest-circulation newspaper, based in Toronto, Ontario, Canada. Its print edition is distributed almost entirely within the province of Ontario...
was published from 1951 to 1981. In 1959 and 1966 staff astronomer Sidney van den Bergh
Sidney van den Bergh
Sidney Van den Bergh, OC, FRS is a retired Canadian astronomer.Born in the Netherlands, son of businessman and politician Sidney James van den Bergh and grandson of Unilever co-founder Samuel van den Bergh, he showed an interest in science from an early age, learning to read with books on astronomy...
composed a database of dwarf galaxies known as the David Dunlap Observatory Catalogue.
In collaboration with the Department of Electrical Engineering, Dr. MacRae established a radio astronomy observatory on the observatory grounds in 1956. The DDO work led to the precise determination of the absolute flux density of Cassiopeia A
Cassiopeia A
Cassiopeia A is a supernova remnant in the constellation Cassiopeia and the brightest astronomical radio source in the sky, with a flux density of 2720 Jy at 1 GHz. The supernova occurred approximately away in the Milky Way. The expanding cloud of material left over from the supernova is now...
at 320 MHz, a radiometric standard as important today as it was when it was reported in 1963. The DDO also built an 18 m radio telescope
Radio telescope
A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...
in Algonquin Park in northern Ontario, co-locating it at the site of the larger Algonquin Radio Observatory
Algonquin Radio Observatory
The Algonquin Radio Observatory is a radio telescope research facility located in the Algonquin Provincial Park in Ontario, Canada. The site's primary instrument is a major 46 m parabolic-dish radio antenna. This instrument is historically famous for taking part in the first successful very...
. This instrument was actively used until 1991, when budget cuts led to it being abandoned. It was later used by a private group as part of a SETI
SETI
The search for extraterrestrial intelligence is the collective name for a number of activities people undertake to search for intelligent extraterrestrial life. Some of the most well known projects are run by the SETI Institute. SETI projects use scientific methods to search for intelligent life...
project, Project TARGET, and has recently been moved to a site outside Shelburne, Ontario
Shelburne, Ontario
Shelburne, Ontario is a town in Dufferin County, Ontario, Canada, located at the intersection of Highway 10 and Highway 89...
.
In 1960 observatory operations formed the narrative framework of the NFB short film Universe. The film was nominated for the 33rd Academy Awards
33rd Academy Awards
The 33rd Academy Awards, honoring the best in film for 1960, were held on April 17, 1961 at the Santa Monica Civic Auditorium in Santa Monica, California...
in the category of best documentary, short subject in 1961. Universe was shown at the 1964 New York World's Fair
1964 New York World's Fair
The 1964/1965 New York World's Fair was the third major world's fair to be held in New York City. Hailing itself as a "universal and international" exposition, the fair's theme was "Peace Through Understanding," dedicated to "Man's Achievement on a Shrinking Globe in an Expanding Universe";...
where it was seen by Stanley Kubrick and Arthur C. Clarke, who were starting work on the film that eventually became 2001: A Space Odyssey
2001: A Space Odyssey (film)
2001: A Space Odyssey is a 1968 epic science fiction film produced and directed by Stanley Kubrick, and co-written by Kubrick and Arthur C. Clarke, partially inspired by Clarke's short story The Sentinel...
. Universe featured future DDO director Donald MacRae
Donald MacRae
Donald Alexander MacRae was a Canadian astronomer.Born in Halifax, Nova Scotia he was the Chair of the Department of Astronomy at the University of Toronto and Director of the David Dunlap Observatory from 1965 to 1978. He was one of a few Canadians who were early Ph.D...
and was narrated by Stanley Jackson.
University of Toronto Professor Tom Bolton
Charles Thomas Bolton
Charles Thomas or Tom Bolton is an American astronomer who was the first astronomer to present strong evidence of the existence of a black hole....
was hired at the DDO in 1970. In 1971 he used data from the Uhuru
Uhuru (satellite)
Uhuru was the first satellite launched specifically for the purpose of X-ray astronomy. It was also known as the X-ray Explorer Satellite, SAS-A , SAS 1, or Explorer 42.The observatory was launched on 12 December 1970 into an initial orbit of about 560 km apogee, 520 km...
X-ray observatory, and Naval Research Laboratory sounding rockets launched from White Sands Missile Range
White Sands Missile Range
White Sands Missile Range is a rocket range of almost in parts of five counties in southern New Mexico. The largest military installation in the United States, WSMR includes the and the WSMR Otera Mesa bombing range...
to find the optical companion star to the X-ray source Cygnus X-1. Those X-ray telescopes had a certain degree of accuracy, but follow-up optical-wavelength studies of possible companions were required to eliminate a shortlist of many stars in the same area of sky. Bolton observed the star HDE 226868 independently of the work by Louise Webster and Paul Murdin, at the Royal Greenwich Observatory, who could not prove that star was Cygnus X-1's optical companion. The high dispersion of the 74 inches (1.9 m) telescope's spectrograph, combined with the 74 inches (1.9 m) aperture was adequate to prove the star was the source of the X-ray emissions and that its behaviour was inconsistent with a normal eclipsing star.
Shifting locations
With the rapid growth of university funding in the 1960s more offices were being built in the downtown campus, and with the opening of the McLennan Labs more and more of the department moved into the new facilities. The Administration Building at the DDO headquartered the Astronomy Department until the 1960s, although the weekly department meetings continued to be held there until 1978. The main library was shifted downtown in 1983. The Cooke Refractor, now almost unused, was later donated to the Canada Science and Technology MuseumCanada Science and Technology Museum
The Canada Science and Technology Museum is located in Ottawa, Ontario, on St. Laurent Boulevard, to the south of the Queensway .-Mission:...
in 1984.
The main reflector at the DDO remained a major instrument into the 1960s, but in the end even the "remote" location Chant had selected was being encroached on by urban sprawl
Urban sprawl
Urban sprawl, also known as suburban sprawl, is a multifaceted concept, which includes the spreading outwards of a city and its suburbs to its outskirts to low-density and auto-dependent development on rural land, high segregation of uses Urban sprawl, also known as suburban sprawl, is a...
. Although some consideration was given to moving the telescope to a new site, in the end it was decided the funds would be better spent on a smaller instrument in a much better location. This led to the building of a 60 cm instrument at Las Campanas
Las Campanas Observatory
Las Campanas Observatory is an astronomical observatory owned and operated by the Carnegie Institution for Science It was established in 1969 and remains the primary observing site of that institution. The headquarters is located in La Serena, Chile and the observatory is in the southern Atacama...
in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
in 1971, creating the University of Toronto Southern Observatory
University of Toronto Southern Observatory
The University of Toronto Southern Observatory was an astronomical observatory built by the University of Toronto at the Las Campanas Observatory in Chile. It hosted a single 60 cm Cassegrain telescope and a small cottage for the operators, located amongst the instruments funded by other...
(UTSO). It was at this location that University of Toronto astronomer Ian Shelton
Ian Shelton
Ian Keith Shelton is a Canadian astronomer famous for discovering SN 1987A, the first modern supernova close and bright enough to be visible to the naked eye.He received his B.Sc...
discovered Supernova 1987A, the first supernova visible to the naked eye in more than 350 years. The UTSO was later closed in 1997 to re-allocate funds to a share of the Gemini Observatory
Gemini Observatory
The Gemini Observatory is an astronomical observatory consisting of two telescopes at sites in Hawai‘i and Chile. Together, the twin Gemini telescopes provide almost complete coverage of both the northern and southern skies...
, and the 60 cm telescope was moved to El Leoncito in Argentina, where the University has a 25% share in observation time.
While University operations continued at the DDO, international observers used about 50% of observing time there. In 2007, the telescope was used by astronomers from Ege University
Ege University
Ege University is a public university in İzmir, Turkey. It was founded in 1955 with the Faculties of Medicine and Faculty of Agriculture...
in Turkey, the Slovak Academy of Sciences
Slovak Academy of Sciences
The Slovak Academy of Sciences SAV is the main scientific and research institution in Slovakia fostering basic and strategic basic research...
in Slovakia, University of Valencia in Spain, Tartu Observatory
Tartu Observatory
The Tartu Observatory is the largest astronomical observatory in Estonia. It is located on the Tõravere hill, about 20 km south-west of Tartu in Nõo Parish, Tartu County...
in Estonia, and the University of Wrocław and Pedagogical University of Cracow
Pedagogical University of Cracow
Pedagogical University of Cracow , located in Kraków, Poland, was founded on May 11, 1946, as the National Higher College of Teacher Training and since gained notoriety for training highly-qualified teaching staff for the local educational...
in Poland.
Closure, sale and re-opening
By the mid-1990s the cutting edge of Canadian university astronomy studies was involved in some of the world's largest observatories: the James Clerk Maxwell TelescopeJames Clerk Maxwell Telescope
The James Clerk Maxwell Telescope is a submillimetre-wavelength telescope at Mauna Kea Observatory in Hawaii. Its primary mirror is 15 metres across: it is the largest astronomical telescope that operates in submillimetre wavelengths of the electromagnetic spectrum...
, 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 Atacama Large Millimeter Array
Atacama Large Millimeter Array
The Atacama Large Millimeter/sub-millimeter Array is an array of radio telescopes in the Atacama desert of northern Chile. Since a high and dry site is crucial to millimeter wavelength operations, the array is being constructed on the Chajnantor plateau at 5000 metres altitude...
and the Gemini Observatory
Gemini Observatory
The Gemini Observatory is an astronomical observatory consisting of two telescopes at sites in Hawai‘i and Chile. Together, the twin Gemini telescopes provide almost complete coverage of both the northern and southern skies...
. None of these telescopes are located in Canada. After the UTSO was closed, in 1998 the Canadian Astronomical Society
Canadian Astronomical Society
The Canadian Astronomical Society is a Canadian society of professional astronomers, founded in 1971 and incorporated in 1983. The society is devoted to the promotion and advancement of knowledge of the universe through research and education, and its membership is open to people with a...
, a society of university astronomers, published a long range plan emphasizing the study of the origins of structure in the universe, a task well-suited to cutting-edge telescopes but ill-suited to the DDO. The long range plan suggested the future of observatories such as the DDO lay in public outreach programs and training. In 2005 Canadian universities joined a partnership to build the Thirty Meter Telescope
Thirty meter telescope
The Thirty Metre Telescope is a proposed ground-based large segmented mirror reflecting telescope to be built on Mauna Kea in Hawaii. The telescope is designed for observations from the near-ultraviolet to the mid-infrared . An adaptive optics system would correct for image blur caused by the...
, expected to cost >$1 billion.
In September 2007, the University stated it was planning on selling the DDO property owing to light pollution
Light pollution
Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association defines light pollution as:...
. The University's governing council voted on the issue during the week of 1 November 2007, and agreed to sell the site to the highest bidder. The 75 ha
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
of land in the midst of a huge subdivision area was expected to fetch $100 million some of which the University planned to use to found a Dunlap Institute to continue astronomical research. The sale was called a "cash grab" by Richmond Hill Mayor David Barrow.
- "There's all kinds of opportunities here that they're just blowing off because they want the money. After 70 years, they're just walking away without looking over their shoulder at what they're leaving behind. That's our disappointment."
For the purposes of the sale, the land was partitioned into a 71 ha
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
Parcel A and a 5 ha Parcel B, upon which sits the Elvis Stojko Hockey Arena and also a park with a 200-metre-wide solar system model
Solar system model
Solar System models, especially mechanical models, called orreries, that illustrate the relative positions and motions of the planets and moons in the Solar System have been built for centuries. While they often showed relative sizes, these models were usually not built to scale...
. The arena is leased by the Town, now from the new owner, until 2015. At the end of June 2008, the University completed the sale of both parcels of the property to Corsica Development Inc., a subsidiary of Metrus Development Inc. for $70 million, a lower price than expected. Observatory staff were laid off and faculty reassigned to the downtown St. George campus. The Town of Richmond Hill planned a hearing with the Conservation Review Board of Ontario to argue for protection of the western 48% of the property including the observatory buildings under the Ontario Heritage Act
Ontario Heritage Act
The Ontario Heritage Act, first enacted on March 5, 1975, allows municipalities and the provincial government to designate individual properties and districts in the Province of Ontario, Canada, as being of cultural heritage value or interest....
; at the hearing, the Richmond Hill Naturalists argued for 100% designation of the property, all the buildings and their contents, and the Observatory Hill Homeowners Association argued for the protection of the heritage woodlots and arboretums. Corsica Development Inc. was also be represented before the CRB. Preliminary hearings took place on September 3 and October 15, 2008. Corsica Development Inc. is administered by Metrus in conjunction with The Conservatory Group and Marel Contracting.
The Conservation Review Board hearing to determine the extent of the Cultural Heritage Landscape designation to be afforded to the Dunlap site took place in Richmond Hill between January 15 to 23, 2009, and the Board recommendation was published on June 4. The Board recommended preservation of the observatory buildings and up to 80% of the property as a cultural heritage landscape. On September 29, 2009 Richmond Hill Town Council voted unanimously in favour of the designating by-law. The Town proceeded with a number of public meetings and reports in late 2009 to craft guidelines for the conservation, planning and design of the property. Corsica Development Inc. undertook an archaeological survey of the property. On April 15, 2010 stemming from an incident on the property in November 2009, Corsica Development Inc. pled guilty in York Region court to 17 counts of cutting a tree without a permit and was issued a fine of $44,880. The company also planted 100 new trees on the property as part of the judgment.
In January 2009, Corsica published the website observatoryhill.ca describing the property, stating, "[We] are in the process of looking for an astronomy club to occupy the observatory and welcome proposals for consideration." On April 22, 2009 Corsica and the Royal Astronomical Society of Canada, Toronto Centre announced an agreement allowing the RASC to provide public education and outreach programs at the observatory, and to operate the 1.88m telescope. On June 14, the RASC Toronto Centre published the website www.theddo.ca to make tickets available for public astronomy nights at the observatory starting on July 18. Astronomy events at the observatory continued through the remainder of 2009 and 2010, such as Perseid meteor shower events both years that drew high attendance and media coverage. These new operations continued in 2011, combined with opportunities such as use of the observatory for a location shoot of the SyFy television series Warehouse 13
Warehouse 13
Warehouse 13 is an American fantasy television series that premiered on July 7, 2009 on the Syfy network.Executive-produced by Jack Kenny and David Simkins, the dramatic comedy from Universal Media Studios has been described as borrowing much from 1980s television series Friday the 13th: The...
.
Dunlap Institute for Astronomy & Astrophysics
In early 2009, coincident with the International Year of AstronomyInternational Year of Astronomy
The International Year of Astronomy was a year-long celebration of astronomy that took place in 2009 to coincide with the 400th anniversary of the first recorded astronomical observations with a telescope by Galileo Galilei and the publication of Johannes Kepler's Astronomia nova in the 17th century...
the University of Toronto started several initiatives connected with the foundation of the Dunlap Institute. The University's Department of Astronomy and Astrophysics, which already had close ties with the Canadian Institute for Theoretical Astrophysics
Canadian Institute for Theoretical Astrophysics
The Canadian Institute for Theoretical Astrophysics is a national research institute funded by the Natural Sciences and Engineering Research Council, located at the University of Toronto in Toronto, Ontario, Canada...
(CITA) announced it was seeking a director for the Dunlap Institute. At the same time Ivan Semeniuk, a well-known Canadian science journalist, joined the Dunlap Institute as Journalist-in-Residence. Dr. Ray Jayawardhana
Ray Jayawardhana
Ray Jayawardhana is an astronomer at the University of Toronto, where he holds the Canada Research Chair in Observational Astrophysics, and an award-winning science writer...
, Canada Research Chair in Observational Astrophysics, announced a series of high-impact advertisements on subways and other vehicles of the Toronto Transit Commission
Toronto Transit Commission
-Island Ferry:The ferry service to the Toronto Islands was operated by the TTC from 1927 until 1962, when it was transferred to the Metro Parks and Culture department. Since 1998, the ferry service is run by Toronto Parks and Recreation.-Gray Coach:...
linking to the Institute's World Wide Web presence at www.coolcosmos.net. The Dunlap Institute, along with CITA and the Department of Astronomy and Astrophysics co-hosted the 2009 annual meeting of CASCA in May, including the annual Helen Sawyer Hogg Lecture sponsored jointly with the Royal Astronomical Society of Canada. The lecture was given by Lawrence M. Krauss
Lawrence M. Krauss
Lawrence Maxwell Krauss is an American theoretical physicist who is professor of physics, Foundation Professor of the School of Earth and Space Exploration, and director of the Origins Project at the Arizona State University. He is the author of several bestselling books, including The Physics of...
. In July 2010 James R. Graham
James R. Graham
James R. Graham is an Irish astrophysicist who works primarily in the fields of infrared astronomy instrumention and adaptive optics.-Biography:...
was announced as the new Dunlap Institute director.
DDO 74 inch (188 cm) telescope contemporaries on commissioning
The telescope debuted ahead of the Plaskett telescope in British Colombia.Three largest telescopes in 1935:
| # | 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 | David Dunlap Observatory |  |
74 inch 188 cm |
224 m (735 ft) |
1935 | Clarence Chant Clarence Chant Clarence Augustus Chant was a Canadian astronomer and physicist.He was born in Hagermans Corners, Ontario to Christopher Chant and Elizabeth Croft. In 1882 he attended Markham High School, where he demonstrated a mathematical ability. After graduation he attended St. Catherines Collegiate... |
| 3 | Plaskett telescope Dominion Astrophysical Obs. Dominion Astrophysical Observatory 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... |
 |
72 inch 182 cm |
230 m (755 ft) |
1918 | John S. Plaskett |
Further reading
- The Cold Light of Dawn: A History of Canadian Astronomy, Richard A. Jarrell, University of Toronto Press, 1988, ISBN 978-0-8020-2653-8
External links
- {official website) http://www.theddo.ca)
- Royal Astronomical Society of Canada - Toronto Centre operations at the David Dunlap Observatory
- Dunlap Institute for Astronomy & Astrophysics
- David Dunlap Observatory Clear Sky Clock forecasts of observing conditions.
- Richmond Hill Naturalists - Save the Observatory Site
- Save David Dunlap Observatory - Flickr Group