TOPIC 02
The Evolution of the Subaru Telescope’s High Resolving Power ― Planet Formation, Exoplanets, Gravitational Lensing ―
The Subaru Telescope equipped with Adaptive Optics (AO), has demonstrated its power in high-resolution infrared observations and played an important role in research on gas clouds called “protoplanetary disks” from which planets form. The combination of AO and the Coronagraphic Imager with Adaptive Optics (CIAO) revealed a protoplanetary disk spiraling around a young star AB Aur. This was pioneering work in the area of protoplanetary disk imaging.
- [Press Release] Spiral Dance in a Planetary Nursery
- [Reference] Fukagawa et al. 2004, ApJ Letters, 605, L53, “Spiral Structure in the Circumstellar Disk around AB Aurigae”
Moreover, the combination also unveiled the detailed structure of the protoplanetary disks surrounding young binary stars, and careful comparison with a theoretical model revealed the behavior of materials fed from outside during the planet formation process for the first time.
- [Press Release] First Direct Imaging of a Young Binary System
- [Reference] Mayama et al. 2009, Science, 327, 306, “Direct Imaging of Bridged Twin Protoplanetary Disks in a Young Multiple Star”
The advent of the High Contrast Instrument with Adaptive Optics (HiCIAO) led the high-resolution observations at the Subaru Telescope to a new phase and eventually enabled us to directly image exoplanets. GJ 504 b, orbiting the sun-like star GJ 504, was the dimmest and coolest exoplanet directly imaged at that time, and could be called a “second Jupiter.”
- [Press Release] Subaru Telescope’s Imaging Discovery of a Second Jupiter Shows the Power and Significance of the SEEDS Project
- [Reference] Kuzuhara et al. 2013, ApJ, 774, 11, “Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504”
The AO system of the Subaru Telescope further developed into a laser guide star system which compensates for effects caused by turbulence in the Earth’s atmosphere. This system allows AO observations without natural guide stars which can be used to compensate for the Earth’s atmosphere. Using this function, researchers observed a gravitationally lensed quasar and successfully detected the galaxy causing gravitational lensing. Ever since, the laser guide star AO system has played an important role in high-resolution observations of galaxies.
- [Press Release] Laser Guide Star Adaptive Optics Sharpens Subaru Telescope’s Eyesight and Opens a New Vision of the Distant Universe
- [Reference] Rusu et al., 2011, ApJ, 738, 30, “SDSS J133401.39+331534.3: A New Subarcsecond Gravitationally Lensed Quasar”