Astronomy Cafe – Aug 16, 2021

Posted by as Astro Cafe

Video transcript of meeting

Location, Location, Location (Plaskett history) – Dennis Crabtree, NRC Herzberg

  • John Stanley Plaskett – took lots of photos
  • Site testing for proposed 72″ telescope used a Cooke 4.5″ equatorially-mounted telescope, mainly operated by W.E. Harper
  • Plaskett’s 1913 tour to Medicine Hat, Penticton, Victoria (for possible observing sites), then the USA before returning to Ottawa
  • Victoria site on Observatory Hill was the obvious choice after site testing
  • Q&A
    • Plaskett’s photos were “lost from memory” – Dennis discovered them in the archives
    • Plaskett hired Edward Fleming as a photographer for the observatory site construction
    • 1 arc second seeing at the Victoria site seems too good to be true – site testing today is done over years, not weeks. See Harper’s paper for the site testing report.
    • Plaskett 72″ mirror was replaced in the 1980s with modern glass
    • High resolution scans of glass plates and negatives are impressive
  • Dennis wants to present these historic photos to the world – archival site

  • Astronomy Cafe – Sep 13 meeting – first in-person Astronomy Cafe in Fairfield
  • Perseid Meteor Shower on Aug 12th – Sid Sidhu
    • All-sky camera – 2 composite photos covering 2 hours each
    • July 13th – sporadic meteor
    • Feb 23rd – another sporadic meteor with gas plasma visible
    • Discussion about meteor trains, fireballs and bolides
  • Jupiter & Perseid photos – Randy Enkin
    • Double transit of Jupiter’s moons with their shadows merging – Christopher Go
    • Perseid Meteor shower photos of note from the Internet
  • Edmonton photos – Dave Robinson
    • Noctilucent clouds – Alister Ling
  • Cave Nebula photos by Dave Payne – processed and presented by John McDonald
  • Events – Lauri Roche
  • Progress on Andromeda Galaxy mosaic – Dave Payne
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