Y
Yuki Hirao
Researcher at Osaka University
Publications - 158
Citations - 2894
Yuki Hirao is an academic researcher from Osaka University. The author has contributed to research in topics: Gravitational microlensing & Planet. The author has an hindex of 24, co-authored 135 publications receiving 2404 citations. Previous affiliations of Yuki Hirao include Goddard Space Flight Center & Max Planck Society.
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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,David P. Bennett,Takahiro Sumi,Ian A. Bond,Leslie A. Rogers,Fumio Abe,Yuichiro Asakura,Aparna Bhattacharya,Aparna Bhattacharya,Martin Donachie,M. Freeman,Akihiko Fukui,Yuki Hirao,Yoshitaka Itow,Naoki Koshimoto,Man Cheung Alex Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,Masayuki Nagakane,K. Onishi,H. Oyokawa,Nicholas J. Rattenbury,To. Saito,A. Sharan,Hiroshi Shibai,Denis J. Sullivan,Paul J. Tristram,Atsunori Yonehara +30 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, and determine the survey sensitivity as a function of planet star mass ratio, q, and projected planet star separation, s, in Einstein radius units.
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,Andrew Gould,Andrew Gould,Jennifer C. Yee,Jennifer A. Johnson,Martin Asplund,Jorge Melendez,Sara Lucatello,L. M. Howes,Andrew McWilliam,Andrzej Udalski,Michał K. Szymański,Igor Soszyński,Radosław Poleski,Radosław Poleski,A. Wyrzykowski,Krzysztof Ulaczyk,Krzysztof Ulaczyk,S. Kozlowski,P. Pietrukowicz,Jan Skowron,P. Mróz,J. M. Pawlak,Fumio Abe,Yuichiro Asakura,Aparna Bhattacharya,Ian A. Bond,David P. Bennett,Yuki Hirao,Masayuki Nagakane,Naoki Koshimoto,Takahiro Sumi,Daisuke Suzuki,P. J. Tristram +35 more
TL;DR: In this paper, a detailed elemental abundance study of 90 F and G dwarfs, turn-off, and subgiant stars in the Galactic bulge has been presented, based on high-resolution spectra acquired during gravitational microlensing events.
Journal ArticleDOI
Spitzer parallax of OGLE-2015-BLG-0966 : a cold Neptune in the Galactic disk
Rachel Street,Andrzej Udalski,S. Calchi Novati,S. Calchi Novati,M. Hundertmark,Wei Zhu,Andrew Gould,Jennifer C. Yee,Yiannis Tsapras,David P. Bennett,U. G. Jørgensen,Martin Dominik,Michael I. Andersen,Etienne Bachelet,Etienne Bachelet,Valerio Bozza,Valerio Bozza,D. M. Bramich,Martin Burgdorf,Arnaud Cassan,Simona Ciceri,Giuseppe D'Ago,Subo Dong,Daniel F. Evans,Shenghong Gu,H. Harkonnen,Tobias C. Hinse,Keith Horne,R. Figuera Jaimes,R. Figuera Jaimes,N. Kains,Eamonn Kerins,Heidi Korhonen,M. Kuffmeier,Luigi Mancini,J. W. Menzies,Shude Mao,Nuno Peixinho,A. Popovas,Markus Rabus,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,Radek Poleski,Radek Poleski,M. Pawlak,Michał K. Szymański,Jan Skowron,P. Mróz,Szymon Kozłowski,Łukasz Wyrzykowski,Paweł Pietrukowicz,Grzegorz Pietrzyński,Igor Soszyński,Krzysztof Ulaczyk,C. A. Beichman,G. Bryden,Sean Carey,B. S. Gaudi,Calen B. Henderson,Calen B. Henderson,Richard W. Pogge,Yossi Shvartzvald,Fumio Abe,Yuichiro Asakura,Aparna Bhattacharya,Ian A. Bond,Martin Donachie,M. Freeman,Akihiko Fukui,Yuki Hirao,K. Inayama,Yoshitaka Itow,Naoki Koshimoto,Man Cheung Alex Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,Masayuki Nagakane,T. 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,C. Han,J-Y. Choi,H. Park,Y. K. Jung,I.-G. Shin +110 more
TL;DR: In this paper, the authors reported the detection of a cold Neptune mplanet = 21 ± 2 M⊕ orbiting a 0.38 m⊙ M dwarf lying 2.5-3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations.
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The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)c
David P. Bennett,David P. Bennett,S. H. Rhie,Andrzej Udalski,Andrew Gould,Andrew Gould,Andrew Gould,Yiannis Tsapras,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,Aparna Bhattacharya,C. S. Botzler,Martin Donachie,M. Freeman,Akihiko Fukui,Yuki Hirao,Yoshitaka Itow,Naoki Koshimoto,Man Cheung Alex Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,Masayuki Nagakane,Kouji Ohnishi,H. Oyokawa,Y. C. Perrott,To. Saito,A. Sharan,Denis J. Sullivan,Takahiro Sumi,Daisuke Suzuki,Daisuke Suzuki,Paul J. Tristram,Atsunori Yonehara,P. C. M. Yock,Michał K. Szymański,Igor Soszyński,Krzysztof Ulaczyk,Łukasz 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,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,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 +88 more
TL;DR: The OGLE-2007-BLG-349 microlensing event has a strong planetary signal that is best fit with a mass ratio q ≈ 3.4 × 10-4, 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 lowest mass ratio planetary microlens: OGLE 2016–BLG–1195Lb
Ian A. Bond,David P. Bennett,Takahiro Sumi,Andrzej Udalski,Daisuke Suzuki,Nicholas J. Rattenbury,Valerio Bozza,Valerio Bozza,Naoki Koshimoto,Fumio Abe,Yuichiro Asakura,Richard K. Barry,Aparna Bhattacharya,Aparna Bhattacharya,Martin Donachie,Phil Evans,Akihiko Fukui,Yuki Hirao,Yoshitaka Itow,Man Cheung Alex Li,C. H. Ling,Kimiaki Masuda,Yutaka Matsubara,Yasushi Muraki,Masayuki Nagakane,K. Ohnishi,Clément Ranc,To. Saito,A. Sharan,Denis J. Sullivan,Paul J. Tristram,T. Yamada,Atsunori Yonehara,Jan Skowron,Michał K. Szymański,Radosław Poleski,Radosław Poleski,P. Mróz,Igor Soszyński,P. Pietrukowicz,S. Kozlowski,Krzysztof Ulaczyk,Krzysztof Ulaczyk,Michał Pawlak +43 more
TL;DR: In this paper, the authors reported the discovery of the lowest mass ratio exoplanet to be found by the microlensing method in the light curve of the event OGLE 2016 -BLG-1195.