日本地球惑星科学連合2018年大会

講演情報

[JJ] ポスター発表

セッション記号 P (宇宙惑星科学) » P-CG 宇宙惑星科学複合領域・一般

[P-CG23] 惑星大気圏・電磁圏

2018年5月20日(日) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:関 華奈子(東京大学大学院理学系研究科)、今村 剛(東京大学大学院 新領域創成科学研究科)、寺田 直樹(東北大学大学院理学研究科、共同)、前澤 裕之(大阪府立大学大学院理学系研究科物理科学科)

[PCG23-P04] Planetary and exoplanetary observations with the Haleakala telescopes and future 1.8-m off-axis telescope PLANETS

*坂野井 健1鍵谷 将人1中川 広務2ベルデュギン アンドレイ3ピローラ ビルップ3ベルデュギナ スベトラーナ4クーン ジェフリー5エミリオ マルチェロ6小原 隆博1笠羽 康正2 (1.東北大学大学院理学研究科惑星プラズマ・大気研究センター、2.東北大学大学院理学研究科、3.フィンランド・トゥルク大学、4.ドイツ・ケーペンハウワー太陽物理研究所、5.ハワイ大・天文研究施設、6.ブラジル・ポンタグロッサ大学)

キーワード:惑星、英外惑星、ハレアカラ、木星、火星、金星

We report the current status of the T40 and T60 telescope activities including the onboard instruments as well as the updates of 1.8-m aperture telescope PLANETS project at Haleakala dedicated to planetary and exoplanetary observations. Continuous monitoring is essential to understand the planetary atmospheric phenomena, and therefore, own facilities with even small- and medium sized telescopes and instruments are important. The location of our telescopes, the Haleakala High Altitude Observatories at the summit of Mt. Haleakala is sufficiently high (3050m), and one of the best sites with clear sky, good seeing, and low humidity conditions.
On the summit, our group is now operating a 40 cm Schmidt-Cassegrain (T40) and 60 cm Cassegrain (T60) telescopes. T40 telescope is mainly observing faint atmospheric features such as Io torus, Mercury, and so on. It has uniquely provided long-term Io torus activities for more than ten years. T60 is now observing planetary atmospheres in visible and infrared range: MIRAHI is a newly developed mid-infrared heterodyne spectrometer. Vispec is a visible spectrometer with coronagraph to observe the Io's sulfur ion torus, Io's sodium cloud, and Enceladus torus. Further, the polarization imager DIPOL-2 is installed to measure the weak polarization of exoplanetary light. These activities are open to any possible collaborators. Our and guest investigators' observations are also linked to Mercury, Venus (Akatsuki), Mars (Mars Express, MAVEN) and Jupiter (Juno) missions.
In addition, we are carrying out a 1.8-m off-axis telescope project PLANETS at Haleakala, Hawaii. This project is managed by the PLANETS Foundation (www.planets.life) is an international collaboration of several institutes from Japan, USA, Germany, Brazil, and France. This off-axis optical system enables very low-stray light contamination and high-contrast in data, i.e., 'high dynamic range'. It will achieve unrivaled scientific capabilities on coronagraphy and polarimetry, aimed at detecting exoplanet reflected light and tenuous planetary exoatmospheres in the Solar system. It will have a Gregoian focus with a FOV of 6' (Fno=13) and a Coude focus with a FOV of 20'' (Fno=49). The main mirror is Clearceram Z-HS with a diameter of 1850 mm, which is now on the final polishing process. We have completed the telescope design and wind analysis of the mechanical support and tracking. The offaxis design is most efficiently contained in a 'splitring' mount. The mount is very stiff and has a first vibration mode above 50 Hz. The PLANETS telescope mechanical design should allow operation without a dome and external wind shielding up to windspeeds of 5m/s. The servo control on both axes will not require high gain and should result in image jitter of less than 0.4'' at frequencies less than 25 Hz during light to moderate winds (windspeeds less than15mi/hr). A bode plot of the proposed control system illustrates that unity gain is achieved beyond about 30 Hz.