Year: 2013
Type: article
Abstract: Most exoplanets detected by direct imaging thus far have been characterized by relatively hot (≳1000 K) and cloudy atmospheres. A surprising feature in some of their atmospheres has been a distinct lack of methane, possibly implying non-equilibrium chemistry. Recently, we reported the discovery of a planetary companion to the Sun-like star GJ 504 using Subaru/HiCIAO within the Strategic Exploration of Exoplanets and Disks with Subaru survey. The planet is substantially colder (<600 K) than previously imaged planets, and has indications of fewer clouds, which implies that it represents a new class of planetary atmospheres with expected similarities to late T-type brown dwarfs in the same temperature range. If so, one might also expect the presence of significant methane absorption, which is characteristic of such objects. Here, we report the detection of deep methane absorption in the atmosphere of GJ 504 b, using the Spectral Differential Imaging mode of HiCIAO to distinguish the absorption features around 1.6 μm. We also report updated JHK photometry based on new K s -band data and a re-analysis of the existing data. The results support the notion that GJ 504 b has atmospheric properties distinct from other imaged exoplanets, and will become a useful reference object for future planets in the same temperature range.
Authors: Markus Janson, Timothy D. Brandt, Masayuki Kuzuhara, David S. Spiegel, Christian Thalmann, Thayne Currie, Mickaël Bonnefoy, Neil Zimmerman, Satoko Sorahana, Takayuki Kotani, Joshua Schlieder, Jun Hashimoto, Tomoyuki Kudo, Nobuhiko Kusakabe, Lyu Abe, Wolfgang Brandner, Joseph C. Carson, Sebastian Egner, Markus Feldt, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Ryo Kandori, Gillian R. Knapp, Jungmi Kwon, Taro Matsuo, Michael W. McElwain, Kyle Mede, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martín, Takao Nakagawa, Tetsuro Nishimura, Tae-Soo Pyo, Eugene Serabyn, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro Takahashi, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Daego Tomono, Edwin L. Turner, Makoto Watanabe, John Wisniewski, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura
Institutions: Queen's University Belfast, Princeton University, National Astronomical Observatory of Japan, The University of Tokyo, Institute for Advanced Study, ETH Zurich, University of Toronto, Max Planck Institute for Astronomy, Nagoya University, Centre National de la Recherche Scientifique, Observatoire de la Côte d’Azur, Université Nice Sophia Antipolis, College of Charleston, Ludwig-Maximilians-Universität München, Goddard Space Flight Center, Eureka Scientific, University of Hawaii at Hilo, The Graduate University for Advanced Studies, SOKENDAI, Kyoto University, Hiroshima University, Consejo Superior de Investigaciones Científicas, Instituto Nacional de Técnica Aeroespacial, Centro de Astrobiología, Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, California Institute of Technology, Jet Propulsion Laboratory, TMT Observatory, Institute of Astronomy and Astrophysics, Academia Sinica, Kavli Institute for the Physics and Mathematics of the Universe, Hokkaido University, University of Oklahoma, Tohoku University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
SDG: Climate action
Open Access status: bronze
Awards: Development of Exoplanet Researches with New IR Technologies, Direct imaging of exoplanets in the vicinity of the star with high contrast instruments, 直接撮像観測による巨大ガス惑星の形成・進化過程の研究, G433322167, G4518818167, RUI: Ground-Based and Space-Based Direct Imaging Surveys for Extrasolar Planets, G58316358, G6273510985, G767601387, G8210229802
OpenAlex ID: W2024916332