Astronomy Cafe – May 8, 2023

Posted by as Astro Cafe

Video transcript of meeting

  • Intro – Marjie Welchframe
  • Centre of the Universe Volunteer Coordinator – Aimee Rossen (info@centreoftheuniverse.org)
    • Volunteer waivers – need to have everyone sign the form after viewing the safety video
    • Volunteer list – access to Observatory Hill
    • Volunteers should arrive before 7pm on Saturday night to avoid congestion at the access gate
  • ORCASat – Prof. Justin Albert
    • This microsat was built at UVic and launched six months ago to the ISS, where it was deployed – ORCASat — Launch
    • ORCASat should burn up next month after six months of operation in low Earth orbit
    • Background
      • Modern cosmology started in 1929 Edwin Hubble’s assertion that the Universe is expanding
      • Cepheid variable stars tell us the absolute magnitude, hence the distance away from Earth. Henrietta Swan-Leavitt’s research enabled this process.
      • Observing past 10*7 Parsecs means using Type 1A SuperNova (White Dwarf), since Cepheids are no longer bright enough to use as a standard candle.
      • Limitations of our Knowledge of Dark Energy 73% of Universe’s mass
      • Calibration of brightness measurements are needed – flux as a function of colour
      • Dark Matter 23% of Universe’s mass
      • Atoms 3% of Universe’s mass
      • The Dark Side of the Universe
      • Supernovae are one of the powerful probes for understanding the eventual fate of the Universe
    • ORCASat is in an ISS-like orbit
      • Needs good coverage above ground observatories, so they can observe Orcasat
      • Photometric calibration – Orcasat’s absolute brightness is compared with standard stars
    • ALTAIR – Airborne Laser for Telescopes Atmospheric Interference Reduction
      • Photometric Calibration using a high altitude balloon
    • A laser photometric ratio star (LPRS) – exciting the Sodium layer
  • I Need More Space-Time – review of a science fair project by Nathan Hellner-Mestleman
    • Predict when our Universe will end
    • Used Wiseman Observatory data for Type 1 SN
      • Spectral lines: Hydrogen epsilon, Hydrogen delta
      • Examined Supernovae 30 million LY to 40 billion LY
      • Found the Hubble Constant to vary from 20 km/sec/Parsec to much bigger
    • Using Slooh data didn’t work out, since Supernovae data levels are too low
    • Project tried to infer how long the Universe will last from changes in brightness of Supernovae
    • Consensus from WMAPS
  • Q&A for both Justin and Nathan
    • Is the Universe finite or infinite? We don’t know, and possibly will never know.
    • Hot, dense start to the Universe – ratio of Hydrogen and Helium verifies this process, as does Nucleosynthesis with Quarks and Gluons (DOE Explains…Quarks and Gluons | Department of Energy).
    • LIGO and other Gravitational Wave observatories should verify how the Universe started (inflation).
  • Events
    • RASC General Assembly – Lauri Roche
    • Beaveree at Camp Barnard – May 27th (9am-2pm) – Bill Weir
    • Island Star Party – Aug 11-13 – Dave Payne
      • Permit for park use is in place
      • More details at next week’s Astro Cafe
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