Department of Physics
More than a thousand extrasolar planets are now known, but most have been detected indirectly through Doppler shifts or photometric detection of eclipses. Extrasolar planets are very challenging to direct directly, ranging from 10^4 to 10^10 times fainter than their parent star. This challenging contrast has been overcome, however, for a few systems. I will discuss the optical science of this problem and the techniques and technologies used - diffraction control through masks and coronagraphs, correction for atmospheric turbulence with adaptive optics, and sophisticated post-processing. The most recent instrument incorporating these technologies is the Gemini Planet Imager (GPI), deployed on the 8-m Gemini South telescope. I will give an overview of GPI’s design and scientific results, including spectroscopic characterization of the atmospheres of young Jovian extrasolar planets and polarimetric properties of circumstellar dust grains. The next steps beyond GPI will involve space missions such as the WFIRST telescope, which will be able to image ‘super-Earth’ planets around nearby stars, and proposed future systems such as deployable formation-flying star shades.
Bruce Macintosh is a Professor in the Stanford University Physics Department who came to Stanford in 2014 from the Lawrence Livermore National Laboratory. He has worked extensively on adaptive optics for astronomical and other applications.
This talk is sponsored by the Department of Applied Physics and by Ginzton Laboratory