Video transcript of meeting
A Special General Meeting (SGM) was held before Astronomy Cafe commenced. After the SGM concluded, members heard a guest speaker and reports.
A Brief History of Galaxies: from the discovery of island universes to a clash of the Titans – Dr. Sara Ellison, UVic Astronomy professor
- Our own Milky Way and other galaxies showing light and dust features
- Deep field taken by JWST
- FOV: a grain of sand held at arm’s length
- thousands of galaxies in the image
- History
- Charles Messier – a 17th century comet hunter who listed 110 objects that are notcomets
- Lord Ross used the 1.8m Leviathan telescope to sketch spiral galaxies
- Shapely-Curtis debate in 1920 about the nature of nebulae
- The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars: Sobel, Dava: 9780143111344: Books – Amazon.ca
- Henrietta Leavitt discovered the Type 1 Cepheid Variables, correlation between the brightness and variations in the luminosity
- Leavitt’s discovery used by Edwin Hubble, who in 1923 settled the Shapely-Curtis debate. The Hubble Law related distance to velocity (red shift), the start of cosmology as we now know it.
- Hubble Tuning Fork classifications of galaxies
- Halton Arp studied Peculiar Galaxies – guide: arpgalaxy.com
- Early modelling of interacting galaxies
- Video – current modelling of interacting galaxies
- Toomre Sequence – showing different morphologies
- Galaxies cluster in groups, which is how they grow mass
- Stellar streams in the Triangulum Galaxy – research at Herzberg
- Tidal streams in the Milky Way are remnants of small galaxies that have interacted in the past
- How a galaxy merger transforms it – simulations predict:
- Isolated disk
- Small group
- Gas funnels to the galaxy centre
- Black hole accretion
- Decay
- Dead Elliptical
- Sara’s research – Sara Ellison – University of Victoria
- Observations of irregular galaxies
- Test whether star formation is quenched as galaxies merge
- Used Canada-France Imaging Survey (CFIS UNIONS) to find merging galaxies using AI
- Q&A
Announcements
- Council meeting coming up – Tue 28th – AGM planning
- Awards Nominations and nominees for Council – contact Reg Dunkley pastpres@victoria.rasc.ca
- AGM will be held online, tentatively on March 13th
- Social dinner will also be held later – awards
- SIGs
- Makers SIG – David Lee
- Beginners SIG – report by Jill Sinkwich
No Astro Cafe next week. Next Astro Cafe will be held on Feb 27th