This meeting is FREE and open to all.
Open to members and non-members alike, our Monthly General Meetings feature club announcements, members’ observation reports, and a headline guest speaker. Speakers typically hail from one of Colorado’s many science or technical organizations and share their experiences on a wide range of astronomy topics.
Meeting Agenda:
- Doors open at 6:30 - drinks and snacks available
- Announcements
- New Member and Guest Introductions
- Presentation by Chris Pickens
- Observing Reports
- Post-meeting social time
****
PRESENTATION:
A Supernova With Broken Symmetry: Evidence from Polarized Light
Supernovae observed in galaxies beyond the Local Group are too distant for astronomers to directly image their shapes. However, the polarized light they emit provides a powerful alternative—a way to probe the geometry of their expanding debris without ever resolving them in an image.
In this talk, Chris will demonstrate the utility of spectropolarimetry, an observational technique that allows us to infer the shape and structure of a supernova from its polarization alone. He will present observations of three “stripped-envelope” supernovae—explosions that have lost much of their outer layers prior to detonation and therefore offer a clearer view of their inner structure.
Among these is the striking case of SN 2016gkg, which exhibits a prominent and persistent elongated axis. About a month after the onset of the explosion, it develops additional complexity: transient, off-axis plumes composed of both high- and low-velocity clumps of hydrogen and helium. These structures scatter in different directions, move at different speeds, and appear to originate from different depths within the ejecta.
While spectropolarimetry cannot uniquely determine the physical mechanisms responsible for these non-axisymmetric features, it provides crucial constraints on the geometry of the explosion and, in turn, valuable insight into the nature of the progenitor star.
OUR PRESENTER:
Chris Pickens is currently a Ph.D. student at the University of Denver (DU), where he works with Chamberlin Director and Professor Jennifer L. Hoffman as part of the Supernova Spectropolarimetry (SNSPOL) Project. His research focuses on the geometry and evolution of supernova explosions through spectropolarimetric observations.
Chris received his B.A. in astronomy and physics from the University of Virginia. He later earned an M.S. in astrophysics from Johns Hopkins University, where he studied stellar populations in starburst galaxies at the Space Telescope Science Institute in Baltimore, Maryland.
Before beginning his doctoral studies, Chris spent fifteen years teaching physics and calculus in independent schools in Baltimore, San Francisco, and Denver. He also served for five years as a science educator at the Denver Museum of Nature & Science.
Chris has an enduring passion for teaching and science communication, and he draws inspiration from the science fiction works of Arthur C. Clarke.
LOCATION:
In-person at the Secular Hub (254 N. Knox Ct., Denver, CO 80219).
Date/time: Monday, April 13th , 7 p.m.
Doors open at 6pm for casual socialization prior to the meeting