Astronomy Cafe – Oct 6, 2025

• Intro & Welcome by Jeff Pivnick
• New members
  • Phil Stooke – PhD UVic, taught at Western University, planetary scientist, now back in Victoria. International Atlas of Mars and International Atlas of the Moon are his books.
  • Vince – started in astronomy as a child in Saskatchewan, member of RASC off-and-on, built his own telescope and mount, 1986 Halley’s Comet started him in astrophotography. Using AI for astrophotography image acquisition.
• New comets this month – Jeff Pivnick
  • 3I/ATLAS – Interstellar comet
  • C/2025 A6 (Lemmon) – long period comet (Oort cloud origin)
  • R/2 SWAN – long period comet
  • Resources
    • Comet Observation database (COBS)
    • Skyhound – Comet Chasing
• The Sun – Jeff Pivnick
  • Fusion of Helios composite solar photo by Andrew McCarthy and Jason Gunnel
  • Solar Observatories and space missions – SOHO, SDO, Parker probe, Solar Orbiter, STEREO, DSCOVR, IRIS
  • Review of the Sun’s parameters, composition, and systems
    • Photosphere – Sun’s surface
      • Sunspots
      • Magnetic flux
      • Limb darkening
    • Chromosphere – lower atmosphere
      • Hydrogen alpha spectrum is visible as red
      • Eclipse reveals the spicules flying off the Sun
      • Hotter than the Photosphere
    • Corona – upper atmosphere
      • Solar flares visible from space-based solar telescopes and from Earth during an eclipse
      • Hotter than the Chromosphere
    • Solar Wind – plasma escapes the Sun’s magnetic field, travelling through the Solar System
    • Magnetic Field
      • Solar prominences
    • Solar flares
      • Coronal Mass Ejection (CME) – cause aurora in Earth’s atmosphere
      • Cycles of activity happen over 9-14 years
    • Solar Zones
      • Convective Zone – below surface
      • Radiative Zone – heat from core but no convection
      • Solar Core – fusion Hydrogen-Deuterium-Helium, detected by Neutrino emissions
  • Tilting Sun app – shows the position of Sun’s equator to put sunspot positions in context
  • Q&A
  • Parker Solar Probe – Natasha van Bentum
    • Mission very close to the Sun
    • Fastest object ever made by humans
    • ParkerBot – virtual assistant for educational purposes about the mission
    • Recent findings about CMEs
    • Video about building the Parker Solar Probe
  • Solar photos
    • Through an 8″ telescope using film by Alex Schmid
    • White and Ha solar photo by Brock Johnston – Photosphere on the left, Chromosphere on the right – different diameter
    • CME and aurora – Sunspot AR3664 on May 10, 2024, then bright aurora a few days later – David Lee
• Titan Shadow Transit of Saturn from Cattle Point Sunday night – David Lee
  • Not successful using a C8 (David) or Maksutov (Kevin Bertles), since seeing was only average and the stability was poor
  • Alex observed two of Saturn’s moons on Saturday
• The Moon – Randy Enkin
  • Using a 6″ Newtonian on an old Celestron mount
  • Sketching the Hevelius crater
  • New space mission to the Moon next year to location nearby
• RASC Victoria Memorabilia – order by contacting Randy Enkin
  • Victoria Centre t-shirts
  • Whiskey glasses
• Events
  • UVic presentation this Wednesday – Northern Star documentary
  • Victoria Centre Annual Dinner at Four Mile Pub – Feb 23
  • 2026 RASC Observers Calendar and observing workbooks – contact Lauri Roche lauri@victoria.rasc.ca
  • Beginners SIG tomorrow night – contact David Lee david@victoria.rasc.ca
  • Victoria Centre Observatory – Reg Dunkley and David will be hosting soon, once the Moon fades a bit

No Astronomy Cafe next week – Thanksgiving!

Video transcript of meeting