Direct detection and characterization of extra-solar planets
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: LLNL and UC are currently leading a team that is building the world’s first dedicated exoplanet imager: the Gemini Planet Imager (GPI). In early 2011 GPI will be delivered to the 8-m Gemini South telescope and begin operations. We are funded to build this $25M instrument, but the Gemini Observatory provides no support to the instrument team to conduct planet hunting with this facility. The proposed activities will support two years of scientific preparation and planning to use GPI and the first year of execution of an exoplanet survey. The goal of our program is to identify and understand the principal physical processes involved in the formation and evolution of planetary systems. The "standard paradigm" in planet formation remains the 18th-century nebular hypothesis of Kant and Laplace. Despite the exploration of our solar system by robotic space probes and the discovery of hundreds of extrasolar planets, our understanding of the origin and evolution of planetary systems and our knowledge of their statistical properties remains elementary: we do not know if our solar system is a typical example; we do not know if the favored formation mechanism for Jupiter, so-called core accretion, is the dominant planet formation pathway; and many of the exotic aspects of newly discovered exoplanetary systems remain unexplained. We are in the midst of a revolution in studying planets and planetary systems. The natural philosophers of the Enlightenment based their speculations on observations of a single solar system: just over a decade ago no extrasolar planets were known, but now over 270 are cataloged and solar systems appear to be a natural outcome of star formation. The known exoplanets are discovered indirectly, either from their gravitational tug on their parent star, or from the dimming of the star during a planet-star eclipse. We do not "see" the planet; moreover, the planets that are discovered are typically massive “super-Jupiters” in close-in orbits. We propose to lead the next and potentially most significant stage of this scientific revolution by focusing on the direct detection and analysis of light emitted and scattered by the planets and small bodies that comprise these systems. The motivation to detect planet light is overwhelming; for example, it is necessary to detect planetary light to establish the composition of their atmospheres and to investigate their thermal history (their cooling and contraction). Moreover, because indirect methods rely on detection of orbital motion, it is increasingly time consuming to find planets at large semimajor axis separation (the period of Saturn at 9.6 AU is 30 years). Direct detection is the only practical way to explore the outer regions (5-30 AU) where the gas and ice giants reside in our solar system; and it is it is precisely in these regions where we can best test the predictions of core accretion and evaluate the viability of alternate formation mechanisms such those that invoke disk instabilities. Jupiter is a billion times fainter than the sun at visible wavelengths, and, until now, direct detection of exoplanets has been beyond our technical grasp. However, a multi-disciplinary approach enabled by the UC/Lab Research Program will allow us to combine maturing adaptive optics technologies embodied in GPI (LLNL), progress in astronomical instrumentation and experimental design (UCB), and deepening knowledge of hydrodynamics and radiative transfer in planetary atmospheres (UCSC) to seize this prize. We therefore have the following goals: 1) combine world-class theoretical, observational, engineering, and experimental talents at Berkeley, Livermore, and Santa Cruz to solve the problem of direct extrasolar planet detection using GPI; 2) provide unique training for a cadre of UC graduate students in these techniques so that they will form the vanguard of scientists that explore this novel field in the next decade; 3) look to the future to exploit the U.C./Caltech 30-m telescope (TMT) for exoplanet science.