Y
Y. Hirao
Researcher at Kobe University
Publications - 21
Citations - 837
Y. Hirao is an academic researcher from Kobe University. The author has contributed to research in topics: Gravitational microlensing & Planet. The author has an hindex of 12, co-authored 21 publications receiving 769 citations. Previous affiliations of Y. Hirao include Nagoya University & Goddard Space Flight Center.
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Journal ArticleDOI
The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass
Daisuke Suzuki,David P. Bennett,Takahiro Sumi,Ian A. Bond,Leslie A. Rogers,Fumio Abe,Yuichiro Asakura,A. Bhattacharya,M. Donachie,M. Freeman,Akihiko Fukui,Y. Hirao,Yoshitaka Itow,Naoki Koshimoto,M. C. A. Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,M. Nagakane,K. Onishi,H. Oyokawa,Nicholas J. Rattenbury,A. Sharan,Hiroshi Shibai,Denis J. Sullivan,Paul J. Tristram,Atsunori Yonehara +27 more
TL;DR: In this article, the authors report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012, finding significant planetary signals in 23 of the 1474 alert events that are well characterized by the MOA II survey data alone, and combine this analysis with the previous analyses of Gould et al. and Cassan et al., bringing the total sample to 30 planets.
Journal ArticleDOI
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. VI. Age and abundance structure of the stellar populations in the central sub-kpc of the Milky Way
Thomas Bensby,Sofia Feltzing,Andrew Gould,Jennifer C. Yee,Jennifer A. Johnson,Martin Asplund,Jorge Melendez,S. Lucatello,L. M. Howes,Andrew McWilliam,Andrzej Udalski,Michał K. Szymański,Igor Soszyński,Radosław Poleski,Łukasz Wyrzykowski,K. Ulaczyk,S. Kozlowski,P. Pietrukowicz,Jan Skowron,P. Mróz,Michał Pawlak,Fumio Abe,Yuichiro Asakura,A. Bhattacharya,Ian A. Bond,David P. Bennett,Y. Hirao,M. Nagakane,N. Koshimoto,Takahiro Sumi,Daisuke Suzuki,P. J. Tristram +31 more
TL;DR: A detailed elemental abundance study of 90 F and G dwarfs, turn-off and subgiant stars in the Galactic bulge has been performed in this paper, and the results strengthen the observational evidence that support the idea of a secular origin for the galactic bulge, formed out of the other main Galactic stellar populations present in the central regions of our Galaxy.
Journal ArticleDOI
Spitzer Parallax of OGLE-2015-BLG-0966: A Cold Neptune in the Galactic Disk
Rachel Street,Andrzej Udalski,S. Calchi Novati,M. Hundertmark,Wei Zhu,Andrew Gould,Jennifer C. Yee,Yiannis Tsapras,David P. Bennett,RoboNet,U. G. Jørgensen,Martin Dominik,Michael I. Andersen,Etienne Bachelet,Valerio Bozza,D. M. Bramich,Martin Burgdorf,Arnaud Cassan,Simona Ciceri,Giuseppe D'Ago,Subo Dong,D. F. Evans,Shenghong Gu,H. Harkonnen,Tobias C. Hinse,Keith Horne,R. Figuera Jaimes,N. Kains,Eamonn Kerins,Heidi Korhonen,M. Kuffmeier,Luigi Mancini,J. W. Menzies,Shude Mao,Nuno Peixinho,A. Popovas,Markus Rabus,Sohrab Rahvar,Clément Ranc,R. Tronsgaard Rasmussen,Gaetano Scarpetta,R. W. Schmidt,Jesper Skottfelt,Colin Snodgrass,John Southworth,Iain A. Steele,Jean Surdej,Eduardo Unda-Sanzana,P. Verma,C. von Essen,Joachim Wambsganss,Yi-Bo Wang,Olivier Wertz,Ogle,R. Poleski,M. Pawlak,Michał K. Szymański,Jan Skowron,P. Mróz,Szymon Kozłowski,L. Wyrzykowski,Paweł Pietrukowicz,Grzegorz Pietrzyński,Igor Soszyński,Krzysztof Ulaczyk,Spitzer Team C. Beichman,G. Bryden,Sean Carey,B. S. Gaudi,Calen B. Henderson,Richard W. Pogge,Yossi Shvartzvald,Fumio Abe,Yuichiro Asakura,A. Bhattacharya,Ian A. Bond,M. Donachie,M. Freeman,Akihiko Fukui,Y. Hirao,K. Inayama,Yoshitaka Itow,Naoki Koshimoto,M. C. A. Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,M. Nagakane,Tsubasa Nishioka,Kouji Ohnishi,H. Oyokawa,Nicholas J. Rattenbury,To. Saito,A. Sharan,Denis J. Sullivan,Takahiro Sumi,Daisuke Suzuki,J. Tristram,Y. Wakiyama,Atsunori Yonehara,KMTNet Modeling Team C. Han,H. Park,Y. K. Jung,I.-G. Shin +104 more
TL;DR: In this article, the detection of a Cold Neptune m_planet=21+/-2M orbiting a 0.38MSol M dwarf lying 2.5-3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations was reported.
Journal ArticleDOI
The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)c
David P. Bennett,S. H. Rhie,Andrzej Udalski,Andrew Gould,Yiannis Tsapras,D. Kubas,Ian A. Bond,J. G. Greenhill,Arnaud Cassan,Nicholas J. Rattenbury,Tabetha S. Boyajian,Jacob K. Luhn,Matthew T. Penny,Jay Anderson,Fumio Abe,A. Bhattacharya,C. S. Botzler,M. Donachie,M. Freeman,Akihiko Fukui,Y. Hirao,Yoshitaka Itow,N. Koshimoto,M. C. A. Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,M. Nagakane,Kouji Ohnishi,H. Oyokawa,Y. C. Perrott,To. Saito,A. Sharan,Denis J. Sullivan,Takahiro Sumi,Daisuke Suzuki,Paul J. Tristram,Atsunori Yonehara,P. C. M. Yock,Michał K. Szymański,Igor Soszyński,Krzysztof Ulaczyk,L. Wyrzykowski,William H. Allen,Darren L. DePoy,Avishay Gal-Yam,B. S. Gaudi,Chang S. Han,I. A. G. Monard,Eran O. Ofek,Richard W. Pogge,Rachel Street,D. M. Bramich,Martin Dominik,Keith Horne,Colin Snodgrass,Iain A. Steele,Michael D. Albrow,Etienne Bachelet,V. Batista,J.-P. Beaulieu,S. Brillant,J. A. R. Caldwell,Andrew A. Cole,Ch. Coutures,S. Dieters,D. Dominis Prester,J. Donatowicz,P. Fouqué,M. Hundertmark,U. G. Jørgensen,N. Kains,S. R. Kane,J.-B. Marquette,J. W. Menzies,K. R. Pollard,Clément Ranc,Kailash C. Sahu,Joachim Wambsganss,Andrew Williams,M. Zub +81 more
TL;DR: The OGLE-2007-BLG-349 microlensing event has a strong planetary signal that is best fit with a mass ratio of $q \approx 3.4\times10^{-4}$, but there is an additional signal due to an additional lens mass, either another planet or another star as mentioned in this paper.
Journal ArticleDOI
The First Neptune Analog or Super-Earth with Neptune-like Orbit: MOA-2013-BLG-605Lb
Takahiro Sumi,Andrzej Udalski,David P. Bennett,Andrew Gould,R. Poleski,Ian A. Bond,N. J. Rattenbury,R. W. Pogge,Thomas Bensby,J. P. Beaulieu,J. B. Marquette,V. Batista,Stephane Brillant,Fumio Abe,Yuichiro Asakura,A. Bhattacharya,M. Donachie,M. Freeman,A. Fukui,Y. Hirao,Yoshitaka Itow,N. Koshimoto,M. C. A. Li,C. H. Ling,Kimiaki Masuda,Yuhei Matsubara,Y. Muraki,M. Nagakane,K. Ohnishi,H. Oyokawa,To. Saito,A. Sharan,Denis J. Sullivan,Daisuke Suzuki,J. Tristram,Atsunori Yonehara,Michał K. Szymański,K. Ulaczyk,S. Kozlowski,L. Wyrzykowski,M. Kubiak,P. Pietrukowicz,Grzegorz Pietrzyński,Igor Soszyński,C. Han,Y. K. Jung,In-Gu Shin,C.-U. Lee +47 more
TL;DR: In this paper, the authors presented the discovery of the first Neptune analog exoplanet or super-Earth with Neptune-like orbit, MOA-2013-BLG-605Lb.