Dominion Astrophysical Observatory research facility


Dominion Astrophysical Observatory closure during the COVID-19 pandemic

In March 2020, the Dominion Astrophysical Observatory (DAO) closed public access to the site, due to the COVID-19 pandemic.

The health and safety of our employees and on-site visitors is our top priority, at the DAO site and across the National Research Council of Canada (NRC). Currently, only essential staff are on site to allow our research operations to continue. As a research institution, and with a limited on-site presence, the DAO is not in a position to ensure safe public access to our site during the pandemic.

We ask for and appreciate your patience and support as we strive to continue to focus our efforts on supporting Canadian research under these unprecedented circumstances.

We look forward to welcoming you back and re-opening the DAO to our community and offering public outreach activities once again, as soon as it is safe to do so.

The Dominion Astrophysical Observatory (DAO) offers capabilities in optical imaging, spectroscopy and spectropolarimetry, and currently operates two research telescopes: the 1.8-metre Plaskett Telescope and the 1.2-metre telescope, which features the high resolution McKellar spectrograph.

The DAO conducts technology research and development associated with instrumentation, facility design and construction projects of the domestic, international and future telescopes they support.

The Observatory has been designated a national historic site because of its important role in establishing Canada's international scientific reputation in astronomy. Over the decades, these telescopes have contributed significantly to our understanding of the rotation, size and mass of the Milky Way, and of the rarefied interstellar medium between the stars. Recent projects include orbital determination of comets and asteroids, spectroscopy of magnetic stars, and ongoing studies of distant quasars and galaxies.

Our capabilities

Since becoming operational in 1918, the Plaskett has accumulated nearly a century of upgrades that make it 10,000 times more sensitive than when it was first built. The 1.8-m Plaskett Telescope can perform optical imaging as well as spectroscopy. Recent improvements include:

  • a 2048 x 4096 pixel CCD camera at the Newtonian imaging focus
  • high-reflectivity coatings on the secondary and spectrograph mirrors
  • upgrades to the observing control system
  • the installation of much more sensitive acquisition and guide cameras at both telescope foci
  • the development of a new polarimeter module for the Cassegrain spectrograph

The 1.2-m telescope is equipped exclusively for optical spectroscopy. Built in 1961, it has been extensively modified and upgraded to internationally competitive standards. Development efforts have allowed for up to 70% of the telescope's observations to be fully automated. Based on the NRC's success with the 1.2-m telescope, automated capabilities are being added to the Plaskett Telescope operating system.

Our observatory's main strengths include hosting long-term observing programs with long blocks of uninterrupted observing time and training next-generation astronomers for their scientific careers.

In addition to making the telescopes and their current instruments available to researchers, the NRC provides online access to a growing collection of archival DAO telescope CCD and photographic spectra and images. These data are available through our Canadian Astronomy Data Centre (CADC) via the DAO Science Archive and the DAO Spectroscopic Plate Archive.

Access and use

Both of DAO's telescopes are available to qualified Canadian and non-Canadian researchers, with time allocated through a peer review process. They are scheduled quarterly and we continue to welcome long-term and thesis projects.