2104 Toronto, provisional designation 1963 PD, is a metallic background asteroid from the outer regions of the asteroid belt, approximately 36 kilometers in diameter. It was discovered on 15 August 1963, by Karl Kamper at the David Dunlap Observatory on plates taken by Sidney van den Bergh at the Karl Schwarzschild Observatory in Tautenburg, Germany. The asteroid was named after the University of Toronto. It was the first asteroid discovered at an observatory in Canada. 
Orbit and classification Toronto is a non- family asteroid from the main belt's background population. It orbits the Sun in the  outer main-belt at a distance of 2.8–3.6 AU once every 5 years and 8 months (2,079 days; semi-major axis of 3.19 AU). Its orbit has an eccentricity of 0.12 and an inclination of 18 ° with respect to the ecliptic.
observation arc begins with a precovery taken at Palomar Observatory in August 1951, or 12 years prior to its official discovery observation at Tautenburg.
Toronto has been characterized as a metallic M-type asteroid by the Wide-field Infrared Survey Explorer (WISE). It is also an assumed  C-type asteroid.
lightcurves of Toronto have been obtained from photometric observations ( ). U=2+/3  The consolidated lightcurve gave a [a] rotation period of 8.97 hours with a brightness amplitude between 0.26 and 0.32 magnitude.
Diameter and albedo
According to the surveys carried out by the Japanese
Akari satellite and the NEOWISE mission of NASA's WISE telescope, Toronto measures between 26.96 and 37.13 kilometers in diameter and its surface has an albedo between 0.099 and 0.292.   
Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and consequently calculates a much larger diameter of 61.04 kilometers based on an absolute magnitude of 9.8.
minor planet was named after the University of Toronto which was celebrating its sesquicentennial at the time of its discovery. It was the first minor planet to be discovered at an observatory in Canada (despite the fact that the credited discovery site is located in Germany). The naming also emphasized the university's central role in the development of Canadian astronomy.  The official  naming citation was published by the Minor Planet Center on 1 February 1979 ( ). M.P.C. 4645
^ a b Aznar (2016) web. Observation of (2104) Toronto from November 2015: Rotation period
hours with a brightness amplitude of 8.97 ±0.01 mag. Quality Code of 3. Summary figures for at the 0.26 ±0.02 LCDB
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"JPL Small-Body Database Browser: 2104 Toronto (1963 PD)" (2017-03-30 last obs.). Jet Propulsion Laboratory . Retrieved . 5 December 2017
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"LCDB Data for (2104) Toronto". Asteroid Lightcurve Database (LCDB) . Retrieved . 5 December 2017
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"Asteroid 2104 Toronto – Proper Elements". AstDyS-2, Asteroids – Dynamic Site . Retrieved . 29 October 2019
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Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv: . 1406.6645 Bibcode: 2014ApJ...791..121M. doi: 10.1088/0004-637X/791/2/121.
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Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode: 2011PASJ...63.1117U. doi: 10.1093/pasj/63.5.1117 . Retrieved . 17 October 2019 ( online, AcuA catalog p. 153)
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Oey, Julian (December 2006). "Lightcurves analysis of 10 asteroids from Leura Observatory". The Minor Planet Bulletin. 33 (4): 96–99. Bibcode: 2006MPBu...33...96O. ISSN 1052-8091 . Retrieved . 5 December 2017
Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv: . 1506.00762 Bibcode: 2015Icar..261...34V. doi: 10.1016/j.icarus.2015.08.007 . Retrieved . 5 December 2017
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