{"id":1768,"date":"2017-06-06T16:31:00","date_gmt":"2017-06-06T07:31:00","guid":{"rendered":"http:\/\/www.astron.s.u-tokyo.ac.jp\/?page_id=1768"},"modified":"2018-03-13T14:48:51","modified_gmt":"2018-03-13T05:48:51","slug":"group_introduction","status":"publish","type":"page","link":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/members\/doa\/tamura_motohide\/group_introduction\/","title":{"rendered":"Introduction to research group: Motohide Tamura"},"content":{"rendered":"<p><\/p>\n<h3>Members<\/h3>\n<ul>\n<li>Motohide Tamura (Prof.)<\/li>\n<li>Norio Narita (Asst. Prof.)<\/li>\n<li>John Livingston (D2)<\/li>\n<li>Taichi Uyama (D2)<\/li>\n<li>Ishizuka (D1)<\/li>\n<li>Yusuke Tanaka (M2)<\/li>\n<li>Jerome de Leon (M1)<\/li>\n<li>Yuka Terada (M1)<\/li>\n<li>Mayuko Mori (B4)<\/li>\n<\/ul>\n<p>Members and their positions are as of 2017 June.<\/p>\n<h3>Summary of our research fields from a general point of view<\/h3>\n<p>\nDirect imaging of exoplanets and their formation sites with Subaru Since the first detection around normal stars in 1995, more than 500 exoplanets have been detected. Furthermore 1000 or more candidates have been recently reported by the Kepler mission. Direct imaging can explore the wide-orbits planets around young stars that are difficult to observe with other methods. Due to the huge contrast between the central star and planet, direct imaging of exoplanets is technically challenging but is finally becoming successful on 8-m class telescopes. Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) is the first Subaru Strategic Program, whose aim is to conduct a direct imaging survey for giant planets as well as protoplanetary\/debris disks at a few to a few tens of AU region around 500 nearby solar-type or more massive young stars devoting 120 Subaru nights for 5 years. We present its early results including detection of planet candidates and discovery of unprecedented details of several protoplanetary disks.\n<\/p>\n<h4>Research Interest and Experience<\/h4>\n<ul>\n<li>Exoplanets, brown dwarfs, star and planet formation, astronomical polarimetry, infrared instrumentation <\/li>\n<li>P.I. of IRD (Infrared Doppler) instrument<\/li>\n<li>P.I. of the SEEDS (Strategic Explorations of Exoplanets and Disks with Subaru) project<\/li>\n<li>P.I. of CIAO (Coronagraphic Imager with Adaptive Optics) for the Subaru Telescope<\/li>\n<li>P.I. of SIRIUS (Simultaneous-color InfraRed Imager for Unbiased Surveys) for the IRSF telescope<\/li>\n<li>P.I. of HiCIAO (High Contrast Instrument for the next generation Adaptive Optics) for Subaru<\/li>\n<\/ul>\n<p>See also a personal webpage of MT (japanese): <a href='http:\/\/esppro.mtk.nao.ac.jp\/~hide\/'>http:\/\/esppro.mtk.nao.ac.jp\/~hide\/<\/a><\/p>\n<h3>Summary of research topics of each member<\/h3>\n<h4>John Livingston (PhD student)<\/h4>\n<p>\nMy research is focused on detecting and characterizing planets via the transit method, which is the most successful planet discovery method to date. By analyzing the transit light curve of a planet host star, we can gain amazingly detailed insights into the physical and orbital properties of the planet, in spite of not being able to \u201csee\u201d the planet directly. Because the transit method provides information which is relative to the properties of the host star, we must also use spectroscopy and other methods to estimate the host star\u2019s physical properties. One consequence of the relative nature of transit light curves is that we can detect smaller planets orbiting smaller stars, since for a constant planet size, the amplitude of the signal increases with decreasing stellar radius. Thus, if we want to discover and study planets similar to Earth, one of the most promising avenues for doing so is to study late-type stars, whose radii are smaller than solar-type stars. It just so happens that nature has been kind to us and produces small planets very frequently around such small stars.\n<\/p>\n<p>\nOne noteworthy recent example of this is the TRAPPIST-1 system, which is a very small star now known to host seven transiting Earth-size planets. Because this star is small and relatively close to us, it will provide many exciting opportunities to study its planets in greater detail in the future. This system is also an example of when transits reveal not only planet sizes, but also their masses. We can use observed deviations in the timing of the planets\u2019 transits to constrain their masses (and eccentricities) by modeling the dynamical interactions between the different planets in the system, known as the transit timing variation (TTV) method.\n <\/p>\n<p>\nSpecial orbital architectures are required to produce TTVs, so for most planetary systems we can only measure planet masses by monitoring the reflex motion of the star induced by the gravitational pull of the planet, known as the radial velocity (RV) method. However, small stars like TRAPPIST-1 are very faint at optical wavelengths, where today\u2019s best radial velocity spectrographs operate (e.g. HARPS, HIRES, HDS). This makes new infrared instruments such as IRD especially exciting, as they will be more sensitive to the light emitted by these small stars (Tamura et al. 2012, Proc. SPIE 8446, doi:10.1117\/12.925885)\u200b. By measuring the masses of small transiting planets, we can learn about their bulk densities and compositions, which will help us assess their habitability, as well as shed light on theories of planet formation and migration.\n<\/p>\n<h4>\u9d5c\u5c71\u592a\u667a \/ Taichi Uyama<\/h4>\n<p><b>\u76f4\u63a5\u64ae\u50cf\u6cd5\u3092\u7528\u3044\u305f\u975e\u5e38\u306b\u82e5\u3044\u7cfb\u5916\u60d1\u661f\u7cfb\u306e\u63a2\u67fb<\/b><br \/>\n\u30001995\u5e74\u306b\u521d\u3081\u3066\u592a\u967d\u3068\u306f\u5225\u306e\u6052\u661f\u3092\u56de\u308b\u60d1\u661f(\u7cfb\u5916\u60d1\u661f)\u304c\u767a\u898b\u3055\u308c\u3001\u73fe\u5728\u307e\u3067\u306b\u6570\u5343\u3082\u306e\u7cfb\u5916\u60d1\u661f\u304c\u5831\u544a\u3055\u308c\u3066\u3044\u308b\u3002\u9a5a\u304f\u3079\u304d\u3053\u3068\u306b\u3001\u3053\u308c\u3089\u306e\u7cfb\u5916\u60d1\u661f\u306f\u592a\u967d\u7cfb\u3068\u5168\u304f\u7570\u8cea\u306a\u3082\u306e\u304c\u591a\u3044\u3002\u3053\u3053\u3067\u7591\u554f\u3068\u306a\u308b\u306e\u306f\u3001\u592a\u967d\u7cfb\u3068\u4ed6\u306e\u661f\u3067\u898b\u3064\u304b\u3063\u305f\u60d1\u661f\u306f\u3069\u3046\u3057\u3066\u5dee\u304c\u751f\u307e\u308c\u305f\u306e\u3060\u308d\u3046\u304b\uff1f\u3068\u3044\u3046\u70b9\u3067\u3042\u308b\u3002\u79d1\u5b66\u8005\u306e\u307f\u306a\u3089\u305a\u3001\u4eba\u985e\u306e\u5922\u3068\u306a\u3063\u3066\u3044\u308b\u300c\u7b2c\u4e8c\u306e\u5730\u7403\u300d\u3084\u300c\u5730\u7403\u5916\u751f\u547d\u4f53\u300d\u3092\u898b\u3064\u3051\u308b\u70ba\u306b\u3082\u3001\u307e\u305a\u3069\u3046\u3084\u3063\u3066\u3053\u308c\u3089\u306e\u60d1\u661f\u304c\u8a95\u751f\u3057\u3066\u6210\u9577\u3057\u305f\u306e\u304b\u3092\u77e5\u308a\u305f\u304f\u306a\u308b\u3002<\/p>\n<p>\u3000\u3055\u3066\u3001\u305d\u308c\u3067\u306f\u3069\u3046\u3084\u3063\u3066\u60d1\u661f\u3092\u691c\u51fa\u3059\u308b\u304b\u3068\u3044\u3046\u3068\u3001\u50d5\u306f\u300c\u76f4\u63a5\u300d\u753b\u50cf\u3068\u3057\u3066\u60d1\u661f\u3092\u767a\u898b\u3057\u3088\u3046\u3068\u3057\u3066\u3044\u308b\u3002\u767e\u805e\u306f\u4e00\u898b\u306b\u5982\u304b\u305a\u3068\u8a00\u3046\u69d8\u306b\u3001\u660e\u3089\u304b\u306b\u60d1\u661f\u3092\u898b\u3064\u3051\u3089\u308c\u308b\u70b9\u3067\u5927\u304d\u306a\u30a4\u30f3\u30d1\u30af\u30c8\u3092\u4e0e\u3048\u308b\u3002\u5b87\u5b99\u306b\u70b9\u5728\u3059\u308b\u6052\u661f\u3068\u6bd4\u3079\u3066\u60d1\u661f\u306f\u975e\u5e38\u306b\u5c0f\u3055\u304f\u6697\u3044\u3082\u306e\u3060\u304c\u3001\u3059\u3070\u308b\u671b\u9060\u93e1(@\u30cf\u30ef\u30a4)\u306e\u3088\u3046\u306a\u4e16\u754c\u7684\u306a\u5927\u578b\u671b\u9060\u93e1\u3092\u7528\u3044\u3066\u7740\u3005\u3068\u691c\u51fa\u6570\u3092\u5897\u3084\u3057\u3066\u3044\u308b\u3002\u3053\u306e\u65b9\u6cd5\u3092\u4f7f\u3063\u3066\u3001\u60d1\u661f\u304c\u751f\u307e\u308c\u308b\u77ac\u9593\u3092\u6349\u3048\u3088\u3046\u3068\u3057\u3066\u3044\u308b\u3002\n<\/p>\n<p><b>Direct Imaging Search for Exoplanet around Young Stellar Object<\/b><br \/>\n Since the first convincing detection of an extrasolar planet (exoplanet) around a main sequence star in 1995, thousands of exoplanets have been confirmed. Surprisingly, many exoplanets are quite different from those in the solar system.  Here one question; what diversifies planets in the Solar system and in other \u201cSolar\u201d systems? In order to detect our dream, not only scientists but also general people, of \u201can Earth 2.0\u201d or \u201cextraterrestrial life\u201d, systematic planet formation and evolution mechanism should be defined.<\/p>\n<p> By the Way, how do we detect exoplanets &#8211; I use \u201cdirect imaging\u201d method. Literally I try to directly detect exoplanets around stars. Compared to stars, planets are much smaller and fainter, however, world-class large aperture telescopes such as Subaru (@Hawaii) enable us to detect exoplanets. I usually use this method aiming at very young exoplanet, namely ongoing planet formation.<\/p>\n<h4>\u77f3\u585a\u5c06\u6597 \/ Masato Ishizuka<\/h4>\n<p>\nFor my master\u2019s thesis, I worked on scrambling technique to improve the performance of Infrared Doppler instrument to be commissioned on Subaru telescope in late 2017. For my PhD, I wish to use IRD for RV observations of nearby exoplanets around late-type host star.\n<\/p>\n<h4>\u7530\u4e2d\u7950\u8f14 \/ Yusuke Tanaka<\/h4>\n<p>\u4ee5\u524d\u306f\u300c\u91cd\u529b\u30de\u30a4\u30af\u30ed\u30ec\u30f3\u30ba\u6cd5\u300d\u3068\u3044\u3046\u7cfb\u5916\u60d1\u661f\u306e\u63a2\u67fb\u65b9\u6cd5\u3092\u7528\u3044\u3001\u9280\u6cb3\u7cfb\u4e2d\u5fc3\u65b9\u5411\u306e\u661f\u3001\u8910\u8272\u77ee\u661f\u3001\u60d1\u661f\u306e\u8cea\u91cf\u306e\u5206\u5e03\u3092\u8abf\u3079\u308b\u7814\u7a76\u3092\u884c\u306a\u3063\u3066\u3044\u305f\u3002\u4eca\u5f8c\u306f\u3059\u3070\u308b\u671b\u9060\u93e1\u306eHSC(Hyper Supreme Cam)\u3068\u3044\u3046\u88c5\u7f6e\u3092\u7528\u3044\u3066\u661f\u5f62\u6210\u9818\u57df\u306b\u304a\u3051\u308b\u4f4e\u8cea\u91cf\u5929\u4f53(\u8910\u8272\u77ee\u661f\u30fb\u6d6e\u904a\u60d1\u661f)\u306e\u5206\u5e03\u3092\u8abf\u3079\u308b\u4e88\u5b9a\u3067\u3042\u308b\u3002<\/p>\n<p> I previously worked on statistical approach with microlensing method.<br \/>\nRecently I am working on imaging of low-mass object such as free floating planets or brown dwarfs with Subaru telescope&#8217;s instrument called HSC. I am planning to reveal how many such objects exist in a star forming region.\n<\/p>\n<h4>Jerome de Leon<\/h4>\n<p>\nI previously worked on direct imaging of circumstellar disk the young stellar object (YSO) named SU Aurigae (SU Aur) using the Subaru telescope. I am planning to conduct polarimetric observation using Subaru\u2019s infrared camera instrument called IRCS of YSO with disks previously observed by K2 for the first time. Aside from direct imaging, I am also interested in transiting exoplanets and studying their atmosphere using the new MuSCAT2 instrument. In the future, I am hoping to work with Subaru telescope\u2019s new integral field unit (IFU) instrument called CHARIS for direct imaging+spectroscopic characterization of young nearby exoplanets.\n<\/p>\n<h4>Yuka Terada<\/h4>\n<p>\nI am interested in research on astrobiology. I previously studied astrobiology research using the next generation radio telescope, especially magnetospheric radio emissions from exoplanets. From now on, I would like to learn the atmospheric observation of extraterrestrial planet by transit spectroscopy observation and various other observation methods and to continue my research.\n<\/p>\n<h4>\u68ee\u4e07\u7531\u5b50 \/ Mayuko Mori<\/h4>\n<p>\n\u79c1\u306e\u8208\u5473\u306f\u3001\u5730\u7403\u5916\u751f\u547d\u3092\u63a2\u3059\u3053\u3068\u3092\u7a76\u6975\u306e\u76ee\u7684\u3068\u3059\u308b\u300c\u30a2\u30b9\u30c8\u30ed\u30d0\u30a4\u30aa\u30ed\u30b8\u30fc\u300d\u3068\u3044\u3046\u7814\u7a76\u5206\u91ce\u306b\u3042\u308b\u3002\u305d\u306e\u305f\u3081\u306e\u5929\u6587\u5b66\u7684\u306a\u30a2\u30d7\u30ed\u30fc\u30c1\u3068\u3057\u3066\u3001\u30c8\u30e9\u30f3\u30b8\u30c3\u30c8\u6cd5\u3092\u306f\u3058\u3081\u3068\u3059\u308b\u69d8\u3005\u306a\u65b9\u6cd5\u3092\u7d44\u307f\u5408\u308f\u305b\u3001\u5019\u88dc\u3068\u306a\u308b\u7cfb\u5916\u60d1\u661f\u3092\u8a73\u7d30\u306b\u8abf\u3079\u3001\u751f\u547d\u304c\u5c45\u4f4f\u3067\u304d\u308b\u300c\u30cf\u30d3\u30bf\u30d6\u30eb\u60d1\u661f\u300d\u304b\u3069\u3046\u304b\u3092\u78ba\u304b\u3081\u308b\u3068\u3044\u3046\u65b9\u6cd5\u304c\u3042\u308b\u3002\u4f8b\u3048\u3070\u3001\u60d1\u661f\u306e\u5bc6\u5ea6\u3084\u8ecc\u9053\u3001\u6e29\u5ea6\u5909\u5316\u3092\u8abf\u3079\u305f\u308a\u3001\u60d1\u661f\u5927\u6c17\u3092\u901a\u904e\u3057\u3066\u304d\u305f\u5149\u3092\u30b9\u30da\u30af\u30c8\u30eb\u306b\u5206\u3051\u3001\u5927\u6c17\u306b\u542b\u307e\u308c\u308b\u6210\u5206\u3092\u8abf\u3079\u305f\u308a\u3059\u308b\u3053\u3068\u3067\u3001\u5730\u7403\u5916\u751f\u547d\u306e\u624b\u304c\u304b\u308a\u3092\u63a2\u3057\u3066\u3044\u308b\u3002\n<\/p>\n<p>\nMy research interest is especially in \u201cAstrobiology,\u201d which is the study of searching for extraterrestrial life. We combine many ways to detect exoplanets, including transit method,in order to examine whether or not each exoplanet is habitable. For example, we compare the density, orbit and temperature gradient of exoplanets, and detect chemical species in the exoplanet atmosphere using transmission spectroscopy.\n<\/p>\n<h3>Pictures of activities<\/h3>\n<p>\nEvery wednesday, one member of the group has to present his own work or recent papers relevant to our research group.<br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"\/tenmon\/wp-content\/uploads\/2017\/06\/picTM1-300x195.png\" alt=\"\" width=\"300\" height=\"195\" class=\"alignnone size-medium wp-image-1769\" srcset=\"https:\/\/www.astron.s.u-tokyo.ac.jp\/tenmon\/wp-content\/uploads\/2017\/06\/picTM1-300x195.png 300w, https:\/\/www.astron.s.u-tokyo.ac.jp\/tenmon\/wp-content\/uploads\/2017\/06\/picTM1-768x498.png 768w, https:\/\/www.astron.s.u-tokyo.ac.jp\/tenmon\/wp-content\/uploads\/2017\/06\/picTM1.png 780w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/>\n<\/p>\n<p>\nFrom left to right: K. Sato, N. Narita, J. Livingston, M. Tamura, T. Uyama, J. de Leon; not in picture: Y. Tanaka and M. Ishizuka<br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"\/tenmon\/wp-content\/uploads\/2017\/06\/picTM2-300x190.png\" alt=\"\" width=\"300\" height=\"190\" class=\"alignnone size-medium wp-image-1770\" srcset=\"https:\/\/www.astron.s.u-tokyo.ac.jp\/tenmon\/wp-content\/uploads\/2017\/06\/picTM2-300x190.png 300w, https:\/\/www.astron.s.u-tokyo.ac.jp\/tenmon\/wp-content\/uploads\/2017\/06\/picTM2.png 764w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/>\n<\/p>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>Members Motohide Tamura (Prof.) Norio Narita (Asst. Prof.) John Livingston (D2) Taichi Uyama (D2) Ishizuka (D1) Yusuke Tanaka (M2) Jerome de Leon (M1) Yuka Terada (M1) Mayuko Mori (B4) Members and their positions are as of 2017 June. Summary of our research fields from a general point of view Direct imaging of exoplanets and their <a class=\"read-more\" href=\"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/members\/doa\/tamura_motohide\/group_introduction\/\">[ Read More ]<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":447,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-1768","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/pages\/1768","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/comments?post=1768"}],"version-history":[{"count":5,"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/pages\/1768\/revisions"}],"predecessor-version":[{"id":2466,"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/pages\/1768\/revisions\/2466"}],"up":[{"embeddable":true,"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/pages\/447"}],"wp:attachment":[{"href":"https:\/\/www.astron.s.u-tokyo.ac.jp\/en\/wp-json\/wp\/v2\/media?parent=1768"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}