Developing Remote Sensing Methods for Characterization of Exoplanets

• Project/Area Number: 25800106
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: The University of Tokyo
• Principal Investigator: Kawahara Hajime 東京大学, 大学院理学系研究科(理学部), 助教 (90649758)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2016: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2015: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2014: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 太陽系外惑星 / キャラクタリゼーション / 直接撮像 / トランジット惑星 / 長周期惑星 / 雪線 / 系外惑星キャラクタリゼーション / ケプラー衛星 / 地球型惑星 / 高分散分光 / 惑星大気 / 宇宙生物学 / 天文光学 / 系外惑星大気 / コロナグラフ / 高コントラスト装置 / 大気散逸 / 恒星惑星相互作用

Outline of Final Research Achievements

Recently, many Earth-sized planets have been reported. However, how do we characterize these planets or constrain the planet formation theory or approach bio-phenomena at the planets? In this research, we developed the methodology for the remote-sensing of the exoplanets. We constructed the method to estimate the obliquity by the photometric variation of the directly imaged planets. We also propose a new concept of the instruments, which combine a coronagraph with a high dispersion spectrograph. So far, it has been considered that the long-period planets are difficult to be characterized. We developed a novel method to detect them and detected seven long period planets in Kepler data.

Research Products

• [Journal Article] Suzaku observations of the merging galaxy cluster Abell2255: The northeast radio relic (2017)
  • Author(s): H. Akamatsu, M. Mizuno, N. Ota, Y.-Y. Zhang, R. J. van Weeren, H. Kawahara, Y. Fukazawa, J. S. Kaastra, M. Kawaharada, K. Nakazawa, T. Ohashi, H.J.A. Rottgering, M. Takizawa, J. Vink, F. Zandanel
  • Journal Title: Astronomy and Astrophysics Volume: 600 Pages: 100-100
  • DOI: 10.1051/0004-6361/201628400
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Masataka Aizawa, Sho Uehara, Kento Masuda, Hajime Kawahara, Yasushi Suto (2017)
  • Author(s): Towards Detection of Exoplanetary Rings Via Transit Photometry: Methodology and a Possible Candidate
  • Journal Title: Astronomical Journal Volume: 印刷中
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Transiting Planet Candidates Beyond the Snow Line Detected by Visual Inspection of 7557 Kepler Objects of Interest (2016)
  • Author(s): Uehara, S., Kawahara, H., Masuda, K., Yamada, S., Aizawa, M.
  • Journal Title: The Astrophysical Journal Volume: 822 Issue: 1 Pages: 2-2
  • DOI: 10.3847/0004-637x/822/1/2
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Frequency Modulation of Directly Imaged Exoplanets: Geometric Effect as a Probe of Planetary Obliquity (2016)
  • Author(s): Hajime Kawahara
  • Journal Title: Astrophysical Journal Volume: 822 Issue: 2 Pages: 112-112
  • DOI: 10.3847/0004-637x/822/2/112
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Frequency Modulation ofDirectly Imaged Exoplanets: Geometric Effect as a Probe of Planetary Obliquity (2016)
  • Author(s): Hajime Kawahara
  • Journal Title: Astrophysical Journal Volume: 印刷中
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Absolute Dimensions of a Flat Hierarchical Triple System KIC 6543674 from the Kepler Photometry (2015)
  • Author(s): Kento Masuda, Sho Uehara, Hajime Kawahara
  • Journal Title: Astrophysical Journal Letters Volume: L37 Issue: 2 Pages: 806-806
  • DOI: 10.1088/2041-8205/806/2/l37
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Lifetime and Spectral Evolution of a Magma Ocean with a Steam Atmosphere: Its Detectability by Future direct Imaging (2015)
  • Author(s): Keiko Hamano, Hajime Kawahara, Yutaka Abe, Masanori Onishi, George L. Hashimoto
  • Journal Title: Astrophysical Journal Volume: 806 Issue: 2 Pages: 216-216
  • DOI: 10.1088/0004-637x/806/2/216
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Suzaku X-ray study of the double radio relic galaxy cluster CIZA J2242.8+5301 (2015)
  • Author(s): H. Akamatsu, R. J. van Weeren, G. A. Ogrean, H. Kawahara, A. Stroe, D. Sobral, M. Hoeft, H. Rottgering, M. Bruggen, J. S. Kaastra
  • Journal Title: Astronomy & Astrophysics Volume: 582 Pages: A87-A87
  • DOI: 10.1051/0004-6361/201425209
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Suzaku observations of the galaxy cluster 1RXS J0603.3+4214: Implications of particle acceleration processes in the "Toothbrush" radio relic (2015)
  • Author(s): Madoka Itahana, Motokazu Takizawa, Hiroki Akamatsu, Takaya Ohashi, Yoshitaka Ishisaki, Hajime Kawahara, Reinout J. van Weeren
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 67 Issue: 6 Pages: 113-113
  • DOI: 10.1093/pasj/psv084
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Theoretical Emission Spectra of Atmospheres of Hot Rocky Super-Earths (2015)
  • Author(s): Ito, Y., Ikoma, M., Kawahara, H., Nagahara, H., Kawashima, Y., and Nakamoto, T.
  • Journal Title: The Astrophysical Journal Volume: 801 Issue: 2 Pages: 144-144
  • DOI: 10.1088/0004-637x/801/2/144
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Spectroscopic Coronagraphy for Planetary Radial Velocimetry of Exoplanets (2014)
  • Author(s): Hajime Kawahara, Naoshi Murakami, Taro Matsuo, Takayuki Kotani
  • Journal Title: The Astrophysical Journal Supplement Series Volume: 212 Issue: 2 Pages: 27-27
  • DOI: 10.1088/0067-0049/212/2/27
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Exploring Hot Gas at Junctions of Galaxy Filaments with Suzaku (2014)
  • Author(s): Ikuyuki Mitsuishi, Hajime Kawahara, Norio Sekiya, Shin Sasaki, Thierry Sousbie and Noriko Y. Yamasaki
  • Journal Title: The Astrophysical Journal Volume: 783 Issue: 2 Pages: 137-148
  • DOI: 10.1088/0004-637x/783/2/137
  • Peer Reviewed
• [Journal Article] Probing the extreme planetary atmosphere of WASP-12b (2013)
  • Author(s): Mark Swain, Pieter Deroo, Giovanna Tinetti, Morgan Hollis, Marcell Tessenyi, Michael Line , Hajime Kawahara, Yuka Fujii, Adam Showman, Sergey Yurchenko
  • Journal Title: Icarus Volume: 225 Issue: 1 Pages: 432-445
  • DOI: 10.1016/j.icarus.2013.04.003
  • Peer Reviewed
• [Journal Article] Starspots-Transit Depth Relation of the Evaporating Planet Candidate KIC 12557548b (2013)
  • Author(s): Hajime Kawahara, Teruyuki Hirano, Kenji Kurosaki, Yuichi Ito, Masahiro Ikoma
  • Journal Title: The Astrophysical Journal Letters Volume: 776 Issue: 1 Pages: L6-L6
  • DOI: 10.1088/2041-8205/776/1/l6
  • Peer Reviewed
• [Journal Article] Validity of Hydrostatic Equilibrium in Galaxy Clusters from Cosmological Hydrodynamical Simulations (2013)
  • Author(s): Suto, Kawahara, et al.
  • Journal Title: Astrophysical Journal Volume: 767 Issue: 1 Pages: 79-79
  • DOI: 10.1088/0004-637x/767/1/79
  • Peer Reviewed
• [Presentation] GPUライトカーブ解析で探るクールな領域の惑星 (2017)
  • Author(s): 河原 創
  • Organizer: 宇宙における生命ワークショップ
  • Place of Presentation: 一橋大学一橋講堂 (東京都千代田区)
  • Year and Date: 2017-03-06
  • Invited
• [Presentation] Transiting planets near and beyond the snow line (2017)
  • Author(s): Hajime Kawahara
  • Organizer: Origin and diversity of planetary systems from the microscope to the telescope
  • Place of Presentation: Nice (France)
  • Year and Date: 2017-02-20
  • Int'l Joint Research / Invited
• [Presentation] FM Exoplanets：反射光光度曲線の周期解析 (2016)
  • Author(s): 河原 創
  • Organizer: 日本天文学会2016年春季年会
  • Place of Presentation: 首都大学東京、東京都、八王子市
  • Year and Date: 2016-03-14
• [Presentation] 地球型系外惑星の探査理論 (2014)
  • Author(s): 河原 創
  • Organizer: 第27回 理論懇シンポジウム
  • Place of Presentation: 国立天文台(東京都)
  • Year and Date: 2014-12-25
  • Invited
• [Presentation] Characterization of Exoplanets with High-contrast & High-Dispersion Instruments on Extremely Large Telescopes (2014)
  • Author(s): Hajime Kawahara
  • Organizer: The 2014 German-Japanese meeting on Exo-Planets and their formation
  • Place of Presentation: Haus der Astronomie, MPI-Astronomy Campus(ドイツ)
  • Year and Date: 2014-11-06
  • Invited
• [Presentation] 系外惑星の分光直接検出のためのSpectroscopic Coronagraph (2014)
  • Author(s): 河原創、村上尚史、松尾太郎、小谷隆行
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 山形大学(山形県)
  • Year and Date: 2014-09-12
• [Presentation] Characterization of Exoplanets with High Contrast Instruments (2014)
  • Author(s): Hajime Kawahara
  • Organizer: Japan Geoscience Meeting 2014
  • Place of Presentation: パシフィコ横浜(神奈川県)
  • Year and Date: 2014-04-28
  • Invited
• [Presentation] Characterization of Exoplanets using Planetary Radial Velocimetry (2014)
  • Author(s): Hajime Kawahara
  • Organizer: Exoclimes III
  • Place of Presentation: Davos Congress Centre (Switzerland, Davos)
• [Presentation] Starspots - Transit Depth Relation of KIC 12557548b (2013)
  • Author(s): Hajime Kawahara, Teruyuki Hirano, Kenji Kurosaki, Yuichi Ito, Masahiro Ikoma
  • Organizer: Kepler Science Conference II
  • Place of Presentation: NASA Ames center, (USA, California)
• [Presentation] 系外惑星探査の進展
  • Author(s): 河原 創
  • Organizer: 研究環シンポジウム：宇宙の化学進化 2014
  • Place of Presentation: 首都大学東京、(東京都八王子市)
  • Invited
• [Presentation] 蒸発惑星のTransit Depth Variation
  • Author(s): 河原 創, 平野照幸, 黒崎健二, 伊藤祐一, 生駒大洋
  • Organizer: 日本天文学会秋期年会
  • Place of Presentation: 東北大学、（宮城県仙台市)