Department Colloquium: Tuesday, November 1, 2022 - The Gaia and Extreme AO Revolution: Discovering, Weighing, and Characterizing Exoplanets and Brown Dwarfs

Event Date: 

Tuesday, November 1, 2022 - 3:45pm

Event Date Details: 

This event will be in-person and on Zoom.

Event Location: 

  • Broida 1640 and Zoom
  • Physics Department Colloquium

This event will be in-person and on Zoom.

The Gaia and Extreme AO Revolution: Discovering, Weighing, and Characterizing Exoplanets and Brown Dwarfs

Timothy Brandt, University of California Santa Barbara

While thousands of exoplanets and brown dwarfs are known, the theoretical models that allow us to interpret their spectra and luminosities are anchored by just a few with independently measured masses, ages (from their host stars), and atmospheric properties (inferred from spectra). I will present a combination of three observational techniques--astrometry, radial velocity, and imaging--to discover, weigh, and characterize massive exoplanets and brown dwarfs. Advances in adaptive optics and infrared instrumentation now enable us to see young exoplanets millions of times fainter than their host stars. Despite huge gains in sensitivity, however, high-contrast imaging surveys remain plagued by a lack of discoveries. I have calibrated a huge data set of stellar reflex motions; it can identify unseen planets and brown dwarfs by the gravitational tugs they exert on their host stars, and enable us to measure their masses and orbits. We have already begun to discover and weigh new substellar companions by targeting accelerating stars. With masses, orbits, and spectra of a growing sample of planets and brown dwarfs, we can finally test models of substellar formation and evolution.

ZOOM INFO: https://ucsb.zoom.us/j/84217234934?pwd=Nk4ya1NLaWVMUVJLMEllcHJzQmRkdz09

Timothy Brandt, University of California Santa Barbara