Optics Tricks to Image Exoplanets

Event Date: 

Tuesday, April 16, 2013 - 4:00pm

Event Location: 

  • Broida 1640

Event Contact: 

Refreshments served at 3:40

Speaker:

Olivier Guyon - University of Arizona and Subaru Observatory

Directly imaging exoplanets is both scientifically exciting but notoriously challenging. Scientifically, obtaining images of rocky planets in the habitable zones of stars is key to finding if and how life developed outside the solar system. Large-scale biological activity can modify the chemical composition of the planet's atmosphere and its surface properties, both of which can be studied by spectrophotometry. The measurement is however extremely challenging, as the planet light is considerably fainter that the host star's light, and the angular separation between the two objects is about 0.1 arcsecond or less.

Conventional imaging systems cannot overcome the high star to planet contrast, and unusual optics are required for imaging exoplanets. I will describe such systems (coronagraphs) and the upcoming scientific opportunities associated with their deployment on ground-based telescopes and in space. I will show that ground-based extremely large telescopes (ELTs) will have the ability to directly image and spectroscopically characterize rocky planets in the habitable zones of nearby M-type stars, thus providing scientific evidence for (or against) the presence of life outside our solar system. Space telescopes operating in optical light are well suited to target Earth-like planets around Sun-like stars.