Astronomy Department Research Project
Directly taking images of exoplanets, which are faint and orbit extremely close to their bright host stars, is challening. Additionally, ground based telescopes are affected by atmospheric turbulence which smears out the light from stars and planets, making it even harder to discern a planet from its host star.
The Gemini Planet Imager (GPI) is a new science instrument that exploits the latest generation of adaptive optics technology, coronagraphy and detectors to be able to correct for atmospheric turbulence, suppress the light of the star, and image young Jupiter-like exoplanets. We have successfully commissioned GPI at the Gemini South telescope in Chile and in 2014 we started a three year science program called GPIES (GPI Exoplanet Survey) that will survey 600 nearby stars for the presence of young giant planets. For each exoplanet we image, we will be able to obtain spectra of its atmosphere to allow us to understand what these planets are made of and what they look like. We will monitor the orbits of these exoplanets to understand their dynamical interaction with the rest of the star system. And by imaging many of these exoplanets, we will begin to understand how planets form and evolve. So far, we have discovered 51 Eridani b, the most Jupiter-like exoplanet ever imaged.
Another object of GPIES is to image and characterize debris disks, which are rings of rocky rubble similar to our own Kuiper Belt. The morphology of debris disks are often a signpost for unseen planets, which are too faint to be imaged directly. However, the gravitational pull of these unseen planets perturbs the morphology of the debris disks, allowing us to infer the precense of a planet and study its dynamical interactions.
The HD 106906 debirsk disk imaged with both the Hubble Space Telescope and the Gemini Planet Imager. Image credit: Paul Kalas / UC Berkeley
Artist rendition of the exoplanet 51 Eridani b. Image credit: Danielle Futselaar / Franck Marchis / SETI Institute.