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The David Dunlap Observatory and black holes

The David Dunlap Observatory in Richmond Hill, Ontario, photographed in 2019.
The David Dunlap Observatory in Richmond Hill, Ontario, photographed in 2019. David Dunlap Observatory NHS-Richmond Hill-Ontario-HPC21775-20190318 · Mhsheikholeslami · Photo source · Photo licence: CC BY-SA 4.0. Resized for display; item previews may be cropped. The image remains under the licence shown.
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The David Dunlap Observatory in Richmond Hill, Ontario, opened in 1935 for the University of Toronto and helped establish academic astronomy in Canada; its dome housed what was once the world’s second-largest telescope. There Thomas Bolton published evidence for a black hole in 1972, and Helen Sawyer Hogg catalogued star clusters.

Scope & context

The observatory and its scientific legacy, not its later ownership.

Sources behind this record

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9 Incredible Science Facts about the University of Toronto ↗

University of Toronto Magazine

Tom Bolton: evidence published in 1972