WASI Monthly Members Meeting
Monthly members meetings are held at 7:00 PM Eastern time on the second Wednesday of the month at the Bear Branch Nature Center, 300 John Owings Rd. Westminster, MD and online via Zoom. There’s a demo or class at 7:00 PM, followed by the featured guest speaker presentation at 7:30 PM.
Our Mrch 11, 2026 meeting will feature a session on Messier Marathons by Curt Roelle. Then, our main speaker is Fr. Richard D’Souza, who is the Superior of the Jesuit community attached to the Vatican Observatory. Fr. D’Souza is interested in studying the formation and evolution of galaxies. In particular, through observations and simulations, he has studied the outer stellar halos of galaxies in order to decipher their accretion histories.
The topic of this talk will be on galactic archaeology. Fr. D’Souza will demonstrate how we can infer the past histories of nearby galaxies like the Milky Way to understand how their past mergers influenced the shape of galaxies. We do this by studying individual stars (resolved stars) in the outskirts of these galaxies using space telescopes like HST and JWST or large ground-based telescopes like Subaru telescope (10m class). The outskirts of these galaxies - commonly call the stellar halo of a galaxy - contains vital information of the past merger history of the galaxy and is made up of the stars of destroyed galaxies. With the aid of models constructed from large computer simulations, we can infer the most massive galaxy that has merged into the main galaxy. Finally, he will demonstrate how this can be applied to our closest neighbour - the Andromeda galaxy. We can infer that the Andromeda galaxy merged with a galaxy half the size of the Milky Way nearly 2-3 Billion years ago, and the stellar disk of Andromeda survived this crash.
Meeting ID: 879 7384 1396
Passcode: 965007
Previous Meetings
You can see videos of previous meetings on our Youtube channel here