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Location
Clayton Hall
Speaker
Dr. Joseph Taylor, 1993 Nobel Prize Laureate Prof. Emeritus at Princeton University
Host
Provencal
Discovery of an orbiting pulsar in 1974 led to increasingly precise measurements that firmly established the existence of of gravitational radiation in the amount and with the properties first predicted by Albert Einstein. Join Dr. Taylor as he describes the torturous path from a theory published in 1915 to the detection of gravitational waves a hundred years later, with many fascinating developments along the way.
Location
SHL215
Speaker
Zsolt Keszthelyi, Queen's University/Royal Military College of Canada
Host
Petit
Surface phenomena, such as mass loss, angular momentum loss, and magnetism have a large impact on the evolution of hot, massive stars. One-dimensional stellar evolution models rely on parametric prescriptions to account for such surface effects; however, the evaluation, revision, and a change in currently-used prescriptions has become inevitable. First, the impact of mass loss will be discussed and an experimental wind routine will be introduced.
Location
SHL215
Speaker
Matthew Penny
Host
Dodson-Robinson
The Wide Field Infrared Survey Telescope (WFIRST) will be NASA's next flagship mission to follow James Webb. Roughly a quarter of WFIRST's primary mission will be spent conducting an exoplanet microlensing survey. The survey will provide a statistical assay of the cold exoplanet population with masses greater than that of Mars and orbits beyond ~1 AU, with a total planet yield comparable to Kepler's.
Location
SHL215
Speaker
Wynn Ho, Haverford College
Host
Holder
Pulsars are famous for having very precisely measured spin rates, rivaling the precision of atomic clocks, and this spin evolves extremely regularly for most pulsars. However, the spin of young pulsars can occasionally undergo sudden changes, known as glitches. Glitches are thought to be due to interactions between normal and superfluid matter in the crust and core of the star. Thus observations and understanding of glitches allow us to probe fundamental nuclear physics and superfluidity. I will give an introduction to pulsar glitches and the superfluid model.
Location
SHL215
Speaker
Amaya Moro-Martin, Space Telescope Science Institute
Host
Gizis
1I/'Oumuamua is the first interstellar interloper to have been detected. Because planetesimal formation and ejection of predominantly icy objects are common by-products of the star and planet formation processes, we address whether 1I/'Oumuamua could be representative of this background population of ejected objects. To do so, we compare the mass density of interstellar objects inferred from its detection to that expected from planetesimal disks under two scenarios: circumstellar disks around single stars and wide binaries, and circumbinary disks around tight binaries.
Location
SHL215
Speaker
Joel Dahlin, NASA Goddard Space Flight Center
Host
Shay
Explosive solar activity in the form of coronal mass ejections and eruptive flares is generally agreed to be powered by the explosive ejection of highly stressed coronal magnetic fields. Magnetic reconnection has long been understood to be the primary driver for the explosive energy release. However, recent studies suggest that reconnection may also play an important role in both the formation and destabilization of the pre-eruptive field.