Eyeing up a Jupiter-like exoplanet
With thousands of exoplanets having been discovered over the past 20 years, the solar system is recognized as presenting just one example among a mind-boggling variety of system architectures: from circumbinary exoplanets (1), systems with tightly packed inner planets (2), water-worlds (3), potential Earth twins (4), super-Earths (5), sub- and super-Neptunes (6), evaporating comet-like planets (7), giant rings (8), and hazy hot Jupiters all the way to extremely long-period lonely massive objects looking more like failed stars than giant planets. So far, the vast majority of these planetary systems have been discovered indirectly by techniques looking at tiny variations in their host star's motion and/or brightness. These techniques have limited remote-sensing capabilities, yet have ushered in an entirely new branch of astrophysics called comparative exoplanetology, putting the solar system and its planets into a universal perspective. On page 64 of this issue, Macintosh et al. (9) present the discovery of a young giant exoplanet with the Gemini Planet Imager (GPI) and a technique called high-contrast imaging. Beyond taking striking pictures (see the figure), the technique promises to yield the most detailed measurements of whole distant planetary systems, including spectroscopy of planet atmospheres and time-resolved astrometry of their orbital motion.
© 2015 American Association for the Advancement of Science.