Past Colloquia
What We Can Learn from Planets in Binary Systems
Cody Hall
Kaitlin Kratter (University of Arizona)
September 19, 2014
14:00 - 15:00
Exoplanet surveys have revealed a surprising array of planetary systems hosted by binary stars. The diversity and architecture of these systems provides insight into the fundamentals of planet formation relevant for a wide range of systems. Moreover, these planets provide an important final boundary condition…
Can We Trust Galaxy Stellar Mass Estimates?
Cody Hall
Dennis Zaritsky (University of Arizona)
September 12, 2014
14:00 - 15:00
Walter Baade, late in his career, was asked if he would choose a career in astrophysics if he had to do it all over again. He replied yes, but only if he could be assured that the ratio of total to selective dust extinction was…
The Decade of the WIMP
Cody Hall
Rocky Kolb (Chicago)
June 20, 2014
14:00 - 15:00
The bulk of the matter in the present universe is dark. The most attractive possibility for the nature of the dark matter is a new species of elementary particle known as a WIMP (a Weakly Interacting Massive Particle). After a discussion of how a WIMP…
Reionization and the Murchison Widefield Array
Cody Hall
Judd Bowman (Arizona State U)
May 30, 2014
14:00 - 15:00
The Murchison Widefield Array (MWA) is the first radio telescope in the Southern Hemisphere designed specifically to explore the astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The MWA has been designed as a compact array consisting of…
The Chemistry of Planet Formation
Cody Hall
Karin Oberg (Harvard)
May 23, 2014
14:00 - 15:00
In the cold and dense stages of star and planet formation, volatile molecules condense out on interstellar grains forming icy mantles. The physics and chemistry of these ices may have a direct impact on planet formation efficiencies and planet bulk compositions. Ice chemistry is also…
Tales from the Zooniverse: Science with a million collaborators
Cody Hall
Chris Lintott (Oxford)
May 16, 2014
14:00 - 15:00
The Zooniverse is the world’s largest and most successful scientific crowdsourcing platform, engaging more than 800,000 volunteers in tasks including classifying galaxies, discovering planets and mapping star formation in the Milky Way. This talk will present highlights from the last six years, including the serendipitous…
Eruptions, disruptions and (repeated) explosions: massive stars at the end of their life: The role of central engines and sustained mass-loss
Cody Hall
Raffaela Margutti (CfA)
May 09, 2014
14:00 - 15:00
Stellar explosions are at the intersection of several critical areas of modern Astronomy: as probes of the early Universe, as electromagnetic signposts of gravitational wave and neutrino emitters, as laboratories for extreme physics. In this talk I present the recent results from my multi-wavelength effort…
Asteroseismology and Exoplanets: A Kepler Success Story
Cody Hall
Daniel Huber (NASA Ames/Oak Ridge)
May 02, 2014
14:00 - 15:00
Asteroseismology – the study of stellar oscillations – is a powerful observational tool to probe the structure and evolution of stars. In addition to the large number of newly discovered exoplanets, the Kepler space telescope has revolutionized asteroseismology by detecting oscillations in thousands of stars…
Testing general relativity with binary pulsars: a whole new game
Cody Hall
Paulo Freire (Max Planck - Bonn)
April 25, 2014
14:00 - 15:00
In this talk I will describe the current renaissance of tests of gravity theories with binary pulsars. I start by describing the classic radiative test of general relativity using the Hulse-Taylor pulsar and the (now) far superior tests done in the double pulsar system. I…
New Probes of Quasar Winds: Multi-Year Variability, Redshifted Troughs, and Hard X-ray Spectroscopy of Broad Absorption Line Quasars
Cody Hall
Niel Brandt (Penn State)
April 11, 2014
14:00 - 15:00
Winds are key parts of quasar nuclear environments, assisting mass accretion and perhaps providing feedback into typical massive galaxies. They are most directly observed via prominent absorption in the UV (e.g., Broad Absorption Lines: BALs) and X-ray bands. I will discuss results coming from three…