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22 results on '"Ling, C. H."'

1. An analysis of binary microlensing event OGLE-2015-BLG-0060

Author

Tsapras, Y., Cassan, A., Ranc, C., Bachelet, E., Street, R., Udalski, A., Hundertmark, M., Bozza, V., Beaulieu, J. P., Marquette, J. B., Euteneuer, E., Figuera Jaimes, R., Calchi Novati, S., Bramich, D. M., Dominik, M., Jaimes, R. Figuera, Horne, K., Mao, S., Menzies, J., Schmidt, R., Snodgrass, C., Steele, I. A., Wambsganss, J., Mróz, P., Szymański, M. K., Soszyński, I., Skowron, J., Pietrukowicz, P., Kozłowski, S., Poleski, R., Ulaczyk, K., PAWLAK, M., Jørgensen, U. G., Skottfelt, J., Popovas, A., Ciceri, S., Korhonen, H., Kuffmeier, M., Evans, D. F., Peixinho, N., Hinse, T. C., Burgdorf, M. J., Southworth, J., Tronsgaard, R., Kerins, E., Andersen, M. I., Rahvar, S., Wang, Y., Wertz, O., Rabus, M., Novati, S. Calchi, D'Ago, G., Scarpetta, G., Mancini, L., Abe, F., Asakura, Y., Bennett, D. P., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Kawasaki, K., Koshimoto, N., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Miyazaki, S., Nagakane, M., Ohnishi, K., Rattenbury, N., Saito, T. O., Sharan, A., Shibai, H., Sullivan, D. J., Sumi, T., Suzuki, D., Tristram, P. J., Yamada, T., Yonehara, A., Figuera Jaimes, R, Calchi Novati, S, D’Ago, G, Jaimes, R Figuera, Novati, S Calchi, Astronomische Rechen-Institut [Heidelberg] (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg]-Universität Heidelberg [Heidelberg], M2A 2019, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Senckenberg Institute, Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science [Washington], NSF Center for EUV Science and Technology, NSF, Ifremer (COP), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), CSNSM PCI, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), School of Chemical and Physical Sciences [Keele], Keele University [Keele], Okayama Astrophysical Observatory, National Astronomical Observatory of Japan (NAOJ), Department of Materials Science [Tokyo], Tokyo Institute of Technology [Tokyo] (TITECH), Laboratory for Intelligent Systems and Informatics, Department of Mechano-Informatics Graduate School of Information Science and Technology, University of Tokyo, Tokyo, Japan (ISI laboratory), University of Tokyo (UTokyo), Atmosphere and Ocean Research Institute [Kashiwa-shi] (AORI), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), NASA Goddard Space Flight Center (GSFC), Astronomical Observatory [Warsaw], Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW), Space Science Department of ESA, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Max-Planck-Institut für Astronomie (MPIA), Ohio State University [Columbus] (OSU), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Kuopio Unit [FMI], Finnish Meteorological Institute (FMI), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (KU), Argelander Institute for Astronomy (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Instituto de Astrofisica de Canarias (IAC), Nagoya University, Department of Physics [Notre Dame], University of Notre Dame [Indiana] (UND), University of Auckland [Auckland], Osaka University [Osaka], Tokyo University of Science [Tokyo], Department of Chemistry, Université de Tsukuba = University of Tsukuba, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Space Science [Toyonaka-shi], Osaka University, Tokyo University Sci. Dept. Sci. & Technol., The University of Tokyo (UTokyo), Science & Technology Facilities Council, University of St Andrews. St Andrews Centre for Exoplanet Science, University of St Andrews. School of Physics and Astronomy, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), University of Copenhagen = Københavns Universitet (UCPH), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
GRAVITATIONAL LENS, T-EFF, Event (relativity), observational [methods], Binary number, Galaxy: Bulge, gravitational lensing: Micro, methods: Observational, techniques: Photometric, Astrophysics, gravitational lensing: micro, GALACTIC BULGE, 01 natural sciences, Galaxy: bulge, photometric [techniques], techniques: photometric, Bulge, Observatory, QB Astronomy, NETWORK, 010303 astronomy & astrophysics, QC, ComputingMilieux_MISCELLANEOUS, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), MILKY-WAY, Astrophysics::Earth and Planetary Astrophysics, methods: observational, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], bulge [Galaxy], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, Settore FIS/05 - Astronomia e Astrofisica, SYSTEMS, SEARCH, 0103 physical sciences, ALGORITHM, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, 010308 nuclear & particles physics, Order (ring theory), DAS, Astronomy and Astrophysics, Light curve, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], QC Physics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], DISCOVERY, astro-ph.EP, micro [gravitational lensing], Parallax, astro-ph.IM, Astrophysics - Earth and Planetary Astrophysics, PLANETS, QB799
Abstract

We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous parts of the light curve was achieved by automated follow-up observations from the robotic telescopes of the Las Cumbres Observatory. We show that, for the first time, all main features of an anomalous microlensing event are well covered by follow-up data, allowing us to estimate the physical parameters of the lens. The strong detection of second-order effects in the event light curve necessitates the inclusion of longer-baseline survey data in order to constrain the parallax vector. We find that the event was most likely caused by a stellar binary-lens with masses $M_{\star1} = 0.87 \pm 0.12 M_{\odot}$ and $M_{\star2} = 0.77 \pm 0.11 M_{\odot}$. The distance to the lensing system is 6.41 $\pm 0.14$ kpc and the projected separation between the two components is 13.85 $\pm 0.16$ AU. Alternative interpretations are also considered., Comment: 13 pages, 5 figures, Published in MNRAS

Published
2019

2. OGLE-2017-BLG-0039: Microlensing Event with Light from a Lens Identified from Mass Measurement

Author

Han, C., Jung, Y. K., Udalski, A., Bond, I., Bozza, V., The, KMTNet Collaboration, Albrow, M. D., Chung, S.-J., Gould, A., Hwang, K.-H., Kim, D., Lee, C.-U., Kim, H.-W., Ryu, Y.-H., Shin, I.-G., Yee, J. C., Shvartzvald, Y., Cha, S.-M., Kim, S.-L., Kim, D.-J., Lee, D.-J., Lee, Y., Park, B.-G., Pogge, R. W., The, OGLE Collaboration Szymański M. K., Mróz, P., Skowron, J., Poleski, R., Soszyński, I., Kozłowski, S., Pietrukowicz, P., Ulaczyk, K., Pawlak, M., The, MOA Collaboration Abe F., Barry, R., Bennett, D. P., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Kawasaki, K., Koshimoto, N., Li, M. C. A., Ling, C. H., Matsubara, Y., Miyazaki, S., Munakata, H., Muraki, Y., Nagakane, M., Ohnishi, K., Ranc, C., Rattenbury, N., Saito, T., Sharan, A., Sullivan, D. J., Sumi, T., Suzuki, Daisuke, Tristram, P. J., Yamada, T., and Yonehara, A.

Subjects
Brightness, 010504 meteorology & atmospheric sciences, Event (relativity), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, gravitational lensing: micro, Gravitational microlensing, 01 natural sciences, Einstein radius, law.invention, law, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, Astronomy and Astrophysics, binaries: general, Space and Planetary Science, Lens (optics), Stars, Astrophysics - Solar and Stellar Astrophysics, Caustic (optics), Astrophysics::Earth and Planetary Astrophysics, Parallax
Abstract

著者人数: 61名（所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 鈴木, 大介), Accepted: 2018-09-27, 資料番号: SA1180205000

Published
2018

3. MOA Data Reveal a New Mass, Distance, and Relative Proper Motion for Planetary System OGLE-2015-BLG-0954L

Author

Bennett, D. P., Bond, I. A., Asakura, Y., Barry, R., Bhattacharya, A., Donachie, M., Evans, P., Hirao, Y., Koshimoto, N., Li, M. C. A., Ling, C. H., Nagakane, M., Ohnishi, K., Ranc, C., Rattenbury, N. J., Saito, To., Sharan, A., Sullivan, D. J., Sumi, T., Tristram, P. J., Yamada, T., Yonehara, A., Abe, Fumio, Fukui, Akihiko, Itow, Yoshitaka, Masuda, Kimiaki, Matsubara, Yutaka, Muraki, Yasushi, and Suzuki, Daisuke

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, Proper motion, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, gravitational lensing: micro, Planetary system, 01 natural sciences, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, planetary systems, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

著者人数: 30名, Accepted: 2017-06-19, 資料番号: SA1170078000

Published
2017

4. MOA-2016-BLG-227Lb: A Massive Planet Characterized by Combining Light-curve Analysis and Keck AO Imaging

Author

Koshimoto, N., Shvartzvald, Y., Bennett, D. P., Penny, M. T., Hundertmark, M., Bond, I. A., Zang, W. C., Henderson, C. B., Suzuki, D., Rattenbury, N. J., Sumi, T., Abe, F., Asakura, Y., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Matsuo, T., Muraki, Y., Nagakane, M., Ohnishi, K., Ranc, C., Saito, To., Sharan, A., Shibai, H., Sullivan, D. J., Tristram, P. J., Yamada, T., Yonehara, A., Gelino, C. R., Beichman, C., Beaulieu, J.-P., Marquette, J.-B., Batista, V., Friedmann, M., Hallakoun, N., Kaspi, S., Maoz, D., Bryden, G., Novati, S. Calchi, Howell, S. B., Wang, T. S., Mao, S., Fouqué, P., Korhonen, H., Jørgensen, U. G., Street, R., Tsapras, Y., Dominik, M., Kerins, E., Cassan, A., Snodgrass, C., Bachelet, E., Bozza, V., Bramich, D. M., University of St Andrews. St Andrews Centre for Exoplanet Science, and University of St Andrews. School of Physics and Astronomy

Subjects
Proper motion, NDAS, Flux, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, micro [Gravitational lensing], law.invention, Telescope, law, Planet, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010308 nuclear & particles physics, Astronomy and Astrophysics, Mass ratio, Light curve, Planetary systems, Stars, QC Physics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of a microlensing planet --- MOA-2016-BLG-227Lb --- with a large planet/host mass ratio of $q \simeq 9 \times 10^{-3}$. This event was located near the $K2$ Campaign 9 field that was observed by a large number of telescopes. As a result, the event was in the microlensing survey area of a number of these telescopes, and this enabled good coverage of the planetary light curve signal. High angular resolution adaptive optics images from the Keck telescope reveal excess flux at the position of the source above the flux of the source star, as indicated by the light curve model. This excess flux could be due to the lens star, but it could also be due to a companion to the source or lens star, or even an unrelated star. We consider all these possibilities in a Bayesian analysis in the context of a standard Galactic model. Our analysis indicates that it is unlikely that a large fraction of the excess flux comes from the lens, unless solar type stars are much more likely to host planets of this mass ratio than lower mass stars. We recommend that a method similar to the one developed in this paper be used for other events with high angular resolution follow-up observations when the follow-up observations are insufficient to measure the lens-source relative proper motion., Comment: 35 pages, 7 figures, 6 tables, Accepted for publication in AJ

Published
2017

5. OGLE-2013-BLG-1761Lb: A Massive Planet Around an M/K Dwarf

Author

Hirao, Y., Udalski, A., Sumi, T., Bennett, D. P., Bond, I. A., Rattenbury, N. J., Suzuki, D., Koshimoto, N., Abe, F., Asakura, Y., Barry, R. K., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Itow, Y., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Matsuo, T., Muraki, Y., Nagakane, M., Ohnishi, K., Saito, To., Sharan, A., Shibai, H., Sullivan, D. J., Tristram, P. J., Yamada, T., Yonehara, A., Poleski, R., Skowron, J., Mr��z, P., Szyma��ski, M. K., Koz��owski, S., Pietrukowicz, P., Soszy��ski, I., Wyrzykowski, ��., and Ulaczyk, K.

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Star (game theory), FOS: Physical sciences, Astronomy and Astrophysics, Radius, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Mass ratio, Planetary system, Light curve, Gravitational microlensing, 01 natural sciences, Einstein radius, Space and Planetary Science, Planet, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. But the detailed light curve analysis ruled out all stellar binary models and shows that the lens to be a planetary system. There is the so-called close/wide degeneracy in the solutions with the planet/host mass ratio of $q \sim (7.5 \pm 1.5) \times 10^{-3}$ and $q \sim (9.3 \pm 2.9) \times 10^{-3}$ with the projected separation in Einstein radius units of $s = 0.95$ (close) and $s = 1.19$ (wide), respectively. The microlens parallax effect is not detected but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located at $D_{\rm L}=6.9_{-1.2}^{+1.0} \ {\rm kpc}$ away from us and the host star is an M/K-dwarf with the mass of $M_{\rm L}=0.33_{-0.18}^{+0.32} \ M_{\odot}$ orbited by a super-Jupiter mass planet with the mass of $m_{\rm P}=2.8_{-1.5}^{+2.5} \ M_{\rm Jup}$ at the projected separation of $a_{\perp}=1.8_{-0.5}^{+0.5} \ {\rm AU}$. The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters can be constrained by the future high resolution imaging by ground large telescopes or HST. If the estimated lens distance is correct, this planet provides another sample for testing the claimed deficit of planets in the Galactic bulge., Comment: 22pages, 7figures, 2tables, submitted to AAS Journals

Published
2017
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6. The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass

Author

Suzuki, D., Bennett, D. P., Sumi, T., Bond, I. A., Rogers, L. A., Abe, F., Asakura, Y., Bhattacharya, A., Donachie, M., Freeman, M., Fukui, A., Hirao, Y., Itow, Y., Koshimoto, N., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Nagakane, M., Onishi, K., Oyokawa, H., Rattenbury, N., Saito, To., Sharan, A., Shibai, H., Sullivan, D. J., Tristram, P. J., and Yonehara, A.

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, Star (game theory), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Function (mathematics), Mass ratio, Type (model theory), 01 natural sciences, Power law, Einstein radius, Distribution (mathematics), Space and Planetary Science, 0103 physical sciences, Sensitivity (control systems), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012. We determine the survey sensitivity as a function of planet-star mass ratio, $q$, and projected planet-star separation, $s$, in Einstein radius units. We find that the mass ratio function is not a single power-law, but has a change in slope at $q \sim 10^{-4}$, corresponding to $\sim 20 M_{\oplus}$ for the median host star mass of $\sim 0.6 M_{\odot}$. We find significant planetary signals in 23 of the 1474 alert events that are well characterized by the MOA-II survey data alone. Data from other groups are used only to characterize planetary signals that have been identified in the MOA data alone. The distribution of mass ratios and separations of the planets found in our sample are well fit by a broken power-law model of the form $dN_{\rm pl}/(d{\rm log} q\ d{\rm log} s) = A (q/q_{\rm br})^n s^m \, {\rm dex}^{-2}$ for $q > q_{\rm br}$ and $dN_{\rm pl}/(d{\rm log} q\ d{\rm log} s) = A (q/q_{\rm br})^p s^m \, {\rm dex}^{-2}$ for $q < q_{\rm br}$, where $q_{\rm br}$ is the mass ratio of the break. We also combine this analysis with the previous analyses of Gould et al. and Cassan et al., bringing the total sample to 30 planets. This combined analysis yields $A = 0.61^{+0.21}_{-0.16}$, $n =-0.93\pm 0.13$, $m = 0.49_{-0.49}^{+0.47}$ and $p = 0.6^{+0.5}_{-0.4}$ for $q_{\rm br}\equiv 1.7\times 10^{-4}$. The unbroken power law model is disfavored with a $p$-value of 0.0022, which corresponds to a Bayes factor of 27 favoring the broken power-law model. These results imply that cold Neptunes are likely to be the most common type of planets beyond the snow line., 67 pages, 18 figures

Published
2016

7. Discovery of a Gas giant Planet in Microlensing Event OGLE-2014-BLG-1760

Author

Bhattacharya, A., Bennett, D. P., Bond, I. A., Sumi, T., Udalski, A., Street, R., Tsapras, Y., Abe, F., Freeman, M., Fukui, A., Hirao, Y., Itow, Y., Koshimoto, N., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Nagakane, M., Ohnishi, K., Rattenbury, N., Saito, T., Sharan, A., Sullivan, D. J., Suzuki, D., Tristram, P. J., Skowron, J., Szymański, M. K., Soszyński, I., Poleski, R., Mróz, P., Kozlowski, S., Pietrukowicz, P., Ulaczyk, K., Wyrzykowski, L., Bachelet, E., Bramich, D. M., D’Ago, G., Dominik, M., Figuera Jaimes, R., Horne, K., Hundertmark, M., Kains, N., Menzies, J., Schmidt, R., Snodgrass, C., Steele, I. A., Wambsganss, J., University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science

Subjects
Proper motion, 010504 meteorology & atmospheric sciences, NDAS, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, micro [Gravitational lensing], Bulge, Planet, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astronomy and Astrophysics, Planetary system, Light curve, Stars, Planetary systems, QC Physics, Space and Planetary Science, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Planetary mass, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the analysis of the planetary microlensing event OGLE-2014-BLG-1760, which shows a strong light curve signal due to the presence of a Jupiter mass-ratio planet. One unusual feature of this event is that the source star is quite blue, with $V-I = 1.48\pm 0.08$. This is marginally consistent with source star in the Galactic bulge, but it could possibly indicate a young source star in the far side of the disk. Assuming a bulge source, we perform a Bayesian analysis assuming a standard Galactic model, and this indicates that the planetary system resides in or near the Galactic bulge at $D_L = 6.9 \pm 1.1 $ kpc. It also indicates a host star mass of $M_* = 0.51 \pm 0.44 M_\odot$, a planet mass of $m_p = 180 \pm 110 M_\oplus$, and a projected star-planet separation of $a_\perp = 1.7\pm 0.3\,$AU. The lens-source relative proper motion is $\mu_{\rm rel} = 6.5\pm 1.1$ mas/yr. The lens (and stellar host star) is predicted to be very faint, so it is most likely that it can detected only when the lens and source stars are partially resolved. Due to the relatively high relative proper motion, the lens and source will be resolved to about $\sim46\,$mas in 6-8 years after the peak magnification. So, by 2020 - 2022, we can hope to detect the lens star with deep, high resolution images., Comment: Submitted to ApJ

Published
2016
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8. DETERMINING THE PHYSICAL LENS PARAMETERS OF THE BINARY GRAVITATIONAL MICROLENSING EVENT MOA-2009-BLG-016

Author

Hwang, K. -H., Han, C., Bond, I. A., Miyake, N., Abe, F., Bennett, D. P., Botzler, C. S., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Muraki, Y., Nishimoto, K., Ohnishi, K., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Skuljan, L., Sullivan, D. J., Sumi, T., Suzuki, D., Sweatman, W. L., Tristram, J., Wada, K., L., P. C. M. Yock D., Depoy, Gaudi, B. S., Gould, A., Lee, C. -U., and Pogge, R. W.

Subjects
Physics, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Light curve, Gravitational microlensing, 01 natural sciences, law.invention, Einstein radius, Lens (optics), Gravitational lens, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, law, 0103 physical sciences, Orbital motion, Astrophysics::Earth and Planetary Astrophysics, Caustic (optics), Parallax, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract

We report the result of the analysis of the light curve of the microlensing event MOA-2009-BLG-016. The light curve is characterized by a short-duration anomaly near the peak and an overall asymmetry. We find that the peak anomaly is due to a binary companion to the primary lens and the asymmetry of the light curve is explained by the parallax effect caused by the acceleration of the observer over the course of the event due to the orbital motion of the Earth around the Sun. In addition, we detect evidence for the effect of the finite size of the source near the peak of the event, which allows us to measure the angular Einstein radius of the lens system. The Einstein radius combined with the microlens parallax allows us to determine the total mass of the lens and the distance to the lens. We identify three distinct classes of degenerate solutions for the binary lens parameters, where two are manifestations of the previously identified degeneracies of close/wide binaries and positive/negative impact parameters, while the third class is caused by the symmetric cycloid shape of the caustic. We find that, for the best-fit solution, the estimated mass of the lower-mass component of the binary is (0.04 +- 0.01) M_sun, implying a brown-dwarf companion. However, there exists a solution that is worse only by \Delta\chi^2 ~ 3 for which the mass of the secondary is above the hydrogen-burning limit. Unfortunately, resolving these two degenerate solutions will be difficult as the relative lens-source proper motions for both are similar and small (~ 1 mas/yr) and thus the lens will remain blended with the source for the next several decades., Comment: 7 pages, 2 tables, and 5 figures

Published
2010

9. OGLE-2013-BLG-0132Lb and OGLE-2013-BLG-1721Lb: Two Saturn-mass Planets Discovered around M-dwarfs

Author

The, OGLE Collaboration, Mroz, Przemek, Udalski, A., Bond, I. A., Skowron, J., Sumi, T., Han, C., Szymanski, M. K., Soszynski, I., Poleski, R., Pietrukowicz, P., Kozlowski, S., Wyrzykowski, L., Ulaczyk, K., The, MOA Collaboration 阿部 文雄, Asakura, Y., Barry, R. K., Bennett, D. P., Bhattacharya, A., Donachie, M., Evans, P., Hirao, Y., Koshimoto, N., Li, M. C. A., Ling, C. H., Nagakane, M., Ohnishi, K., Ranc, C., Rattenbury, N. J., Saito, To., Sharan, A., Sullivan, D. J., Tristram, P. J., Yamada, T., Yonehara, A., The, MOA Collaboration Abe Fumio, Fukui, Akihiko, Itow, Yoshitaka, Masuda, Kimiaki, Matsubara, Yutaka, Muraki, Yasushi, and Suzuki, Daisuke

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, planets and satellites: detection, 010504 meteorology & atmospheric sciences, Saturn (rocket family), FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, gravitational lensing: micro, 01 natural sciences, Space and Planetary Science, Planet, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract

著者人数: 41名, Accepted: 2017-09-25, 資料番号: SA1170174000

Published
2017

10. THE EXTREME MICROLENSING EVENT OGLE-2007-BLG-224: TERRESTRIAL PARALLAX OBSERVATION OF A THICK-DISK BROWN DWARF

Author

Gould, A., Udalski, A., Monard, B., Horne, K., Dong, Subo, Miyake, N., Sahu, K., Bennett, D. P., Wyrzykowski, Ł., Soszyński, I., Szymański, M. K., Kubiak, M., Pietrzyński, G., Szewczyk, O., Ulaczyk, K., Allen, W., Christie, G. W., Depoy, D. L., Gaudi, B. S., Han, C., Lee, C.-U., Mccormick, J., Natusch, T., Park, B.-G., Pogge, R. W., Allan, A., Bode, M. F., Bramich, D. M., Burgdorf, M. J., Dominik, M., Fraser, S. N., Kerins, E., Mottram, C., Snodgrass, C., Steele, I. A., Street, R., Tsapras, Y., Abe, F., Bond, I. A., Botzler, C. S., Fukui, A., Furusawa, K., Hearnshaw, J. B., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Nagaya, M., Ohnishi, K., Okumura, T., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Skuljan, L., Sullivan, D. J., Sumi, T., Sweatman, W. L., Tristram, P. J., Yock, P. C. M., Albrow, M., Beaulieu, J. P., Coutures, C., Calitz, H., Caldwell, J., Fouqué, P., Martin, Roland, Williams, A., Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Astrophysics Research Institute [Liverpool] (ARI), Liverpool John Moores University (LJMU), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Astronomical Objects, Solar System, gravitational lensing, Brown dwarf, FOS: Physical sciences, Astrophysics, Gravitational microlensing, 01 natural sciences, law.invention, stars: low-mass, law, 0103 physical sciences, Thick disk, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Lens (optics), Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), astrometry, Astrophysics::Earth and Planetary Astrophysics, Parallax, Event (particle physics), brown dwarfs
Abstract

Parallax is the most fundamental technique to measure distances to astronomical objects. Although terrestrial parallax was pioneered over 2000 years ago by Hipparchus (ca. 140 BCE) to measure the distance to the Moon, the baseline of the Earth is so small that terrestrial parallax can generally only be applied to objects in the Solar System. However, there exists a class of extreme gravitational microlensing events in which the effects of terrestrial parallax can be readily detected and so permit the measurement of the distance, mass, and transverse velocity of the lens. Here we report observations of the first such extreme microlensing event OGLE-2007-BLG-224, from which we infer that the lens is a brown dwarf of mass M=0.056 +- 0.004 Msun, with a distance of 525 +- 40 pc and a transverse velocity of 113 +- 21 km/s. The velocity places the lens in the thick disk, making this the lowest-mass thick-disk brown dwarf detected so far. Follow-up observations may allow one to observe the light from the brown dwarf itself, thus serving as an important constraint for evolutionary models of these objects and potentially opening a new window on sub-stellar objects. The low a priori probability of detecting a thick-disk brown dwarf in this event, when combined with additional evidence from other observations, suggests that old substellar objects may be more common than previously assumed., Comment: ApJ Letters, in press, 15 pages including 2 figures

Published
2009

11. OGLE-2012-BLG-0563Lb : a Saturn-mass planet around an M dwarf with the mass constrained by Subaru AO imaging

Author

Fukui, A., Gould, A., Sumi, T., Bennett, D. P., Bond, I. A., Han, C., Suzuki, D., Beaulieu, J.-P., Batista, V., Udalski, A., Street, R. A., Tsapras, Y., Hundertmark, Markus Peter Gerhard, Abe, F., Bhattacharya, A., Freeman, M., Itow, Y., Ling, C. H., Koshimoto, N., Masuda, K., Matsubara, Y., Muraki, Y., Ohnishi, K., Philpott, L. C., Rattenbury, N., Saito, T., Sullivan, D. J., Tristram, P. J., Yonehara, A., Choi, J.-Y., Christie, G. W., DePoy, D. L., Dong, Subo, Drummond, J., Gaudi, B. S., Hwang, K.-H., Kavka, A., Lee, C.-U., McCormick, J., Natusch, T., Ngan, H., Park, H., Pogge, R. W., Shin, I.-G., Tan, T.-G., Yee, J. C., Szymański, M. K., Pietrzyński, G., Soszyński, I., Poleski, R., Kozłowski, S., Pietrukowicz, P., Ulaczyk, K., Wyrzykowski, Ł., Bramich, D. M., Browne, Paul, Dominik, Martin, Horne, Keith Douglas, Ipatov, S., Kains, N., Snodgrass, C., Steele, I. A., The Royal Society, Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
Metallicity, NDAS, FOS: Physical sciences, Astrophysics, Type (model theory), Gravitational microlensing, 01 natural sciences, Planet, 0103 physical sciences, QB Astronomy, 010303 astronomy & astrophysics, QC, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010308 nuclear & particles physics, photometric [Techniques], Astronomy and Astrophysics, Planetary system, Mass ratio, Light curve, Exoplanet, Planetary systems, detection [Planets and satellites], gaseous planets [Planets and satellites], high angular resolution [Techniques], QC Physics, 13. Climate action, Space and Planetary Science, late-type [Stars], Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio ~1 x 10^{-3}. Intensive photometric observations of a high-magnification microlensing event allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK'-band images obtained by the Subaru/AO188 and IRCS instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of a spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3^{+0.6}_{-0.8} kpc from us, and consists of an M dwarf (0.34^{+0.12}_{-0.20} M_sun) orbited by a Saturn-mass planet (0.39^{+0.14}_{-0.23} M_Jup) at the projected separation of 0.74^{+0.26}_{-0.42} AU (close model) or 4.3^{+1.5}_{-2.5} AU (wide model). The probability of contamination in the host star's flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the (J-Ks) and (H-Ks) colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass (0.2, Comment: 17 pages, 11 figures, an error in Figure 11 in the published version corrected

Published
2015

12. Microlensing Discovery of a Population of Very Tight, Very Low-mass Binary Brown Dwarfs

Author

Choi, J.-Y., Han, C., Udalski, A., Sumi, T., Gaudi, B. S., Gould, A., Bennett, D. P., Dominik, M., Beaulieu, J.-P., Tsapras, Y., Bozza, V., Abe, F., Bond, I. A., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Suzuki, K., Sweatman, W. L., Suzuki, D., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., The MOA Collaboration, Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Skowron, J., Kozłowski, S., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Pietrukowicz, P., The OGLE Collaboration, Almeida, L. A., DePoy, D. L., Dong, Subo, Gorbikov, E., Jablonski, F., Henderson, C. B., Hwang, K.-H., Janczak, J., Jung, Y.-K., Kaspi, S., Lee, C.-U., Malamud, U., Maoz, D., McGregor, D., Muñoz, J. A., Park, B.-G., Park, H., Pogge, R. W., Shvartzvald, Y., Shin, I.-G., Yee, J. C., The μFUN Collaboration, Alsubai, K. A., Browne, P., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Fang, X.-S., Finet, F., Glitrup, M., Grundahl, F., Gu, S.-H., Hardis, S., Harpsøe, K., Hinse, T. C., Hornstrup, A., Hundertmark, M., Jessen-Hansen, J., Jrgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M. N., Lundkvist, M., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Snodgrass, C., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Zimmer, F., MiNDSTEp Consortium, The, Albrow, M. D., Bachelet, E., Batista, V., Brillant, S., Cassan, A., Cole, A. A., Coutures, C., Dieters, S., Dominis Prester, D., Donatowicz, J., Fouqué, P., Greenhill, J., Kubas, D., Marquette, J.-B., Menzies, J. W., Sahu, K. C., Zub, M., The PLANET Collaboration, Bramich, D. M., Horne, K., Steele, I. A., Street, R. A., The RoboNet Collaboration, Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
binaries: general, gravitational lensing: micro, 010504 meteorology & atmospheric sciences, Population, Events, Brown dwarf, Minimum mass, Binary number, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, micro [Gravitational lensing], Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Physics, education.field_of_study, Galactic bulge, general [Binaries], Systems, Search, Astronomy and Astrophysics, Stars, Extrasolar planets, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Low Mass, Gravitational lens
Abstract

Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass of the brown-dwarf mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low-mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 Msun and 0.034 Msun, and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field brown-dwarf binaries known. The discovery of a population of such binaries indicates that brown dwarf binaries can robustly form at least down to masses of ~0.02 Msun. Future microlensing surveys will measure a mass-selected sample of brown-dwarf binary systems, which can then be directly compared to similar samples of stellar binaries., 7 pages, 5 figures, 3 tables, ApJ submitted

Published
2013

13. MOA-2010-BLG-328Lb: A SUB-NEPTUNE ORBITING VERY LATE M DWARF?

Author

Furusawa, K., Udalski, A., Sumi, T., Bennett, D. P., Bond, I. A., Gould, A., Jorgensen, U. G., Snodgrass, C., Prester, D. Dominis, Albrow, M. D., Abe, F., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Harris, P., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Szymanski, M. K., Soszynski, I., Kubiak, M., Poleski, R., Ulaczyk, K., Pietrzynski, G., Wyrzykowski, L., Choi, J. Y., Christie, G. W., DePoy, D. L., Dong, S., Drummond, J., Gaudi, B. S., Han, C., Hung, L. -W., Jung, Y. -K., Lee, C. -U., McCormick, J., Moorhouse, D., Natusch, T., Nola, M., Ofek, E., Park, B. G., Park, H., Pogge, R. W., Shin, I. -G., Skowron, J., Thornley, G., Yee, J. C., Alsubai, K. A., Bozza, V., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dominik, M., Finet, F., Gerner, T., Hardis, S., Harpsoe, K., Hinse, T. C., Hundertmark, M., Kains, N., Kerins, E., Liebig, C., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Schafer, S., Schonebeck, F., Southworth, J., Surdej, J., Wambsganss, J., Street, R. A., Bramich, D. M., Steele, I. A., Tsapras, Y., Horne, K., Donatowicz, J., Sahu, K. C., Bachelet, E., Batista, V., Beatty, T. G., Beaulieu, J. -P., Bennett, C. S., Black, C., Bowens-Rubin, R., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A. A., Corrales, E., Coutures, C., Dieters, S., Fouque, P., Greenhill, J., Henderson, C. B., Kubas, D., Marquette, J. -B., Martin, R., Menzies, J. W., Shappee, B., Williams, A., Wouters, D., van Saders, J., Zellem, R., Zub, M., Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
gravitational lensing: micro, planetary systems, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, Gravitational microlensing, 01 natural sciences, micro [Gravitational lensing], Settore FIS/05 - Astronomia e Astrofisica, Neptune, Planet, 0103 physical sciences, QB Astronomy, 010303 astronomy & astrophysics, QC, 0105 earth and related environmental sciences, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Xallarap, Astronomy and Astrophysics, Planetary systems, QC Physics, Space and Planetary Science, Orbital motion, Parallax, Event (particle physics), Astrophysics - Earth and Planetary Astrophysics
Abstract

We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and planetary masses of Mh = 0.11+/-0.01 M_{sun} and Mp = 9.2+/-2.2M_Earth, corresponding to a very late M dwarf and sub-Neptune-mass planet, respectively. The system lies at DL = 0.81 +/- 0.10 kpc with projected separation r = 0.92 +/- 0.16 AU. Because of the host's a-priori-unlikely close distance, as well as the unusual nature of the system, we consider the possibility that the microlens parallax signal, which determines the host mass and distance, is actually due to xallarap (source orbital motion) that is being misinterpreted as parallax. We show a result that favors the parallax solution, even given its close host distance. We show that future high-resolution astrometric measurements could decisively resolve the remaining ambiguity of these solutions., Comment: 30 pages, 6 figures. accepted for publication in ApJ. Figure 1 and 2 are updated

Published
2013

14. Microlensing Binaries with Candidate Brown Dwarf Companions

Author

Shin, I.-G., Han, C., Gould, A., Udalski, A., Sumi, T., Dominik, M., Beaulieu, J.-P., Tsapras, Y., Bozza, V., Szymański, M. K., Kubiak, M., Soszyński, I., Pietrzyński, G., Poleski, R., Ulaczyk, K., Pietrukowicz, P., Kozłowski, S., Skowron, J., Wyrzykowski, Ł., The OGLE Collaboration, Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Kobara, S., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Omori, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., The MOA Collaboration, Christie, G. W., Depoy, D. L., Dong, S., Gal-Yam, A., Gaudi, B. S., Hung, L.-W., Janczak, J., Kaspi, S., Maoz, D., McCormick, J., McGregor, D., Moorhouse, D., Muñoz, J. A., Natusch, T., Nelson, C., Pogge, R. W., Tan, T.-G., Polishook, D., Shvartzvald, Y., Shporer, A., Thornley, G., Malamud, U., Yee, J. C., Choi, J.-Y., Jung, Y.-K., Park, H., Lee, C.-U., Park, B.-G., Koo, J.-R., The μFUN Collaboration, Bajek, D., Bramich, D. M., Browne, P., Horne, K., Ipatov, S., Snodgrass, C., Steele, I., Street, R., Alsubai, K. A., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Dreizler, S., Fang, X.-S., Grundahl, F., Gu, C.-H., Hardis, S., Harpsøe, Kennet Bomann West, Hinse, T. C., Hundertmark, M., Jessen-Hansen, J., Jørgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, Mikkel Nørup, Lundkvist, M., Mancini, L., Mathiasen, M., Hornstrup, A., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, Jesper Fælling, Southworth, J., Surdej, J., Tregloan-Reed, J., Wertz, O., Zimmer, F., Albrow, M. D., Batista, V., Brillant, S., Caldwell, J. A. R., Calitz, J. J., Cassan, A., Cole, A., Cook, K. H., Corrales, E., Coutures, Ch., Dieters, S., Dominis Prester, D., Donatowicz, J., Fouqué, P., Greenhill, J., Hill, K., Hoffman, M., Kane, S. R., Kubas, D., Marquette, J.-B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Sahu, K. C., Wambsganss, J., Williams, A., Vinter, Christian, and Zub, M.

Subjects
Physics, 010308 nuclear & particles physics, Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, gravitational lensing: micro, Astrophysics, Light curve, Gravitational microlensing, 01 natural sciences, Einstein radius, Stars, binaries: general, Settore FIS/05 - Astronomia e Astrofisica, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Planet, 0103 physical sciences, brown dwarfs, Parallax, Low Mass, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation history. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing events discovered during 2004 - 2011 observation seasons. Based on the low mass ratio criterion of q < 0.2, we found 7 candidate events, including OGLE-2004-BLG-035, OGLE-2004-BLG-039, OGLE-2007-BLG-006, OGLE-2007-BLG-399/MOA-2007-BLG-334, MOA-2011-BLG-104/OGLE-2011-BLG-0172, MOA-2011-BLG-149, and MOA-201-BLG-278/OGLE-2011-BLG-012N. Among them, we are able to confirm that the companions of the lenses of MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149 are brown dwarfs by determining the mass of the lens based on the simultaneous measurement of the Einstein radius and the lens parallax. The measured mass of the brown dwarf companions are (0.02 +/- 0.01) M_Sun and (0.019 +/- 0.002) M_Sun for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events with well covered light curves increases with new generation searches., 10 pages, 9 figures, 4 tables

Published
2012

15. Characterizing Lenses and Lensed Stars of High-magnification Single-lens Gravitational Microlensing Events with Lenses Passing over Source Stars

Author

Choi, J.-Y., Shin, I.-G., Park, S.-Y., Han, C., Gould, A., Sumi, T., Udalski, A., Beaulieu, J.-P., Street, R., Dominik, M., Allen, W., Almeida, L. A., Bos, M., Christie, G. W., Depoy, D. L., Dong, S., Drummond, J., Gal-Yam, A., Gaudi, B. S., Henderson, C. B., Hung, L.-W., Jablonski, F., Janczak, J., Lee, C.-U., Mallia, F., Maury, A., McCormick, J., McGregor, D., Monard, L. A. G., Moorhouse, D., Muñoz, J. A., Natusch, T., Nelson, C., Park, B.-G., Pogge, R. W., 'TG\\' Tan, T.-G., Thornley, G., Yee, J. C., The μFUN Collaboration, Abe, F., Barnard, E., Baudry, J., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Kobara, S., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Omori, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Suzuki, D., Suzuki, K., Sweatman, W. L., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., The MOA Collaboration, Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Kozłowski, S., Pietrukowicz, P., The OGLE Collaboration, Albrow, M. D., Bachelet, E., Batista, V., Bennett, C. S., Bowens-Rubin, R., Brillant, S., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Dominis Prester, D., Donatowicz, J., Fouqué, P., Greenhill, J., Kane, S. R., Menzies, J., Sahu, K. C., Wambsganss, J., Williams, A., Zub, M., The PLANET Collaboration, Allan, A., Bramich, D. M., Browne, P., Clay, N., Fraser, S., Horne, K., Kains, N., Mottram, C., Snodgrass, C., Steele, I., Tsapras, Y., The RoboNet Collaboration, Alsubai, K. A., Bozza, V., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Dreizler, S., Finet, F., Gerner, T., Glitrup, M., Grundahl, F., Hardis, S., Harpsøe, K., Hinse, T. C., Hundertmark, M., Jørgensen, U. G., Kerins, E., Liebig, C., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Schäfer, S., Schönebeck, F., Skottfelt, Jesper Fælling, Surdej, J., Southworth, J., Zimmer, F., and MiNDSTEp Consortium, The

Subjects
Physics, 010308 nuclear & particles physics, Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, gravitational lensing: micro, Astrophysics, Mass ratio, Light curve, Gravitational microlensing, 01 natural sciences, Galaxy: bulge, Galaxy: bulge, gravitational lensing: micro, Einstein radius, law.invention, Lens (optics), Stars, Astrophysics - Solar and Stellar Astrophysics, Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, law, 0103 physical sciences, Surface brightness, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We present the analysis of the light curves of 9 high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/MOA-2011-BLG-325. For all events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For 7 events, we measure the Einstein radii and the lens-source relative proper motions. Among them, 5 events are found to have Einstein radii less than 0.2 mas, making the lenses candidates of very low-mass stars or brown dwarfs. For MOA-2011-BLG-274, especially, the small Einstein radius of $\theta_{\rm E}\sim 0.08$ mas combined with the short time scale of $t_{\rm E}\sim 2.7$ days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of $\sim 0.84\ M_\odot$ is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we find planetary signals for none of events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio., Comment: 14 pages, 12 figures, 5 tables

Published
2012

16. Characterizing Low-Mass Binaries From Observation of Long Time-scale Caustic-crossing Gravitational Microlensing Events

Author

Shin, I.-G, Han, C., Choi, J.-Y, Udalski, A., Sumi, T., Gould, A., Bozza, V., Dominik, M., Fouque´, P., Horne, K., Szyman´ski, M. K., Kubiak, M., Soszyn´ski, I., Pietrzyn´ski, G., Poleski, R., Ulaczyk, K., Pietrukowicz, P., Kozłowski, S., Skowron, J., Wyrzykowski, Ł., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Itow, Y., Kobara, S., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohmori, K., Ohnishi, K., Rattenbury, N. J., Saito, To, Sullivan, D. J., Suzuki, D., Suzuki, K., Sweatman, W. L., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., MOA Collaboration, Bramich, D. M., Snodgrass, C., Steele, I. A., Street, R. A., Tsapras, Y., RoboNet Collaboration, Alsubai, K. A., Browne, P., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Dreizler, S., Fang, X.-S, Grundahl, Frank, Gu, C.-H, Hardis, S., Harpsøe, Kennet Bomann West, Hinse, T. C., Hornstrup, Allan, Hundertmark, M., Jessen-Hansen, Jens, Jørgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M., Lunkkvist, M., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Almeida, L. A., Batista, V., Christie, G., DePoy, D. L., Dong, Subo, Gaudi, B. S., Henderson, C., Jablonski, F., Lee, C.-U, McCormick, J., McGregor, D., Moorhouse, D., Natusch, T., Ngan, H., Park, S.-Y., Pogge, R. W., Tan, T.-G, Thornley, G., Yee, J. C., Albrow, M. D., Bachelet, E., Beaulieu, J.-P, Brillant, S., Cassan, A., Cole, A. A., Corrales, E., Coutures, C., Dieters, S., Dominis Prester, D., Donatowicz, J., Greenhill, J., Kubas, D., Marquette, J.-B, Menzies, J. W., Sahu, K. C., and Zub, M.

Subjects
binaries: general, gravitational lensing: micro, 010504 meteorology & atmospheric sciences, Binary number, FOS: Physical sciences, Astrophysics, Gravitational microlensing, 01 natural sciences, Einstein radius, micro [Gravitational lensing], Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, Binary star, binaries: general, gravitational lensing: micro, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Orbital elements, Physics, general [Binaries], Observational techniques, Astronomy and Astrophysics, Light curve, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Low Mass
Abstract

Despite astrophysical importance of binary star systems, detections are limited to those located in small ranges of separations, distances, and masses and thus it is necessary to use a variety of observational techniques for a complete view of stellar multiplicity across a broad range of physical parameters. In this paper, we report the detections and measurements of 2 binaries discovered from observations of microlensing events MOA-2011-BLG-090 and OGLE-2011-BLG-0417. Determinations of the binary masses are possible by simultaneously measuring the Einstein radius and the lens parallax. The measured masses of the binary components are 0.43 $M_{\odot}$ and 0.39 $M_{\odot}$ for MOA-2011-BLG-090 and 0.57 $M_{\odot}$ and 0.17 $M_{\odot}$ for OGLE-2011-BLG-0417 and thus both lens components of MOA-2011-BLG-090 and one component of OGLE-2011-BLG-0417 are M dwarfs, demonstrating the usefulness of microlensing in detecting binaries composed of low-mass components. From modeling of the light curves considering full Keplerian motion of the lens, we also measure the orbital parameters of the binaries. The blended light of OGLE-2011-BLG-0417 comes very likely from the lens itself, making it possible to check the microlensing orbital solution by follow-up radial-velocity observation. For both events, the caustic-crossing parts of the light curves, which are critical for determining the physical lens parameters, were resolved by high-cadence survey observations and thus it is expected that the number of microlensing binaries with measured physical parameters will increase in the future., Comment: 8 pages, 5 figures, 4 tables

Published
2012

17. Microlensing Binaries Discovered through High-Magnification Channel

Author

Shin, I.-G., Choi, J.-Y., Park, S.-Y., Han, C., Gould, A., Sumi, T., Udalski, A., Beaulieu, J.-P., Dominik, M., Allen, W., Bos, M., Christie, G. W., Depoy, D. L., Dong, S., Drummond, J., Gal-Yam, A., Gaudi, B. S., Hung, L.-W., Janczak, J., Kaspi, S., Lee, C.-U., Mallia, F., Maoz, D., Maury, A., McCormick, J., Monard, L. A. G., Moorhouse, D., Muñoz, J. A., Natusch, T., Nelson, C., Park, B.-G., Pogge, R. W., Polishook, D., Shvartzvald, Y., Shporer, A., Thornley, G., Yee, J. C., μFUN Collaboration, Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Kobara, S., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Omori, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., MOA Collaboration, Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Kozłowski, S., Pietrukowicz, P., OGLE Collaboration, Albrow, M. D., Batista, V., Bramich, D. M., Brillant, S., Caldwell, J. A. R., Calitz, J. J., Cassan, A., Cole, A., Cook, K. H., Corrales, E., Coutures, Ch., Dieters, S., Dominis Prester, D., Donatowicz, J., Fouqué, P., Greenhill, J., Hoffman, M., Jørgensen, U. G., Kane, S. R., Kubas, D., Marquette, J.-B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Sahu, K. C., Wambsganss, J., Williams, A., Vinter, Christian, Zub, M., PLANET Collaboration, Allan, A., Browne, P., Horne, K., Snodgrass, C., Steele, I., Street, R., Tsapras, Y., RoboNet Collaboration, Alsubai, K. A., Bozza, V., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Dreizler, S., Finet, F., Gerner, T., Glitrup, M., Grundahl, F., Hardis, S., Harpsøe, Kennet Bomann West, Hessman, F. V., Hinse, T. C., Hundertmark, M., Kains, N., Kerins, E., Liebig, C., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Schäfer, S., Schönebeck, F., Skottfelt, Jesper Fælling, Surdej, J., Southworth, J., Zimmer, F., and MiNDSTEp Consortium

Subjects
binaries: general, gravitational lensing: micro, Binary number, FOS: Physical sciences, Astrophysics, Gravitational microlensing, 01 natural sciences, law.invention, Settore FIS/05 - Astronomia e Astrofisica, Planet, law, 0103 physical sciences, binaries: general, gravitational lensing: micro, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Mass ratio, Light curve, 3. Good health, Lens (optics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Degeneracy (mathematics), Event (particle physics)
Abstract

Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of 8 binary lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a $3\sigma$ confidence level for 3 events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretic prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is $q\sim 0.1$, making the companion of the lens a strong brown-dwarf candidate., Comment: 10 figures, 6 tables, 26 pages

Published
2011

18. A sub-Saturn mass planet, MOA-2009-BLG-319Lb

Author

Miyake, N., Sumi, T., Dong, Subo, Street, R., Mancini, L., Gould, A., Bennett, D. P., Tsapras, Y., Yee, J. C., Albrow, M. D., Bond, I. A., Fouque, P., Browne, P., Han, C., Snodgrass, C., Finet, F., Furusawa, K., Harpsoe, K., Allen, W., Hundertmark, M., Freeman, M., Suzuki, D., Abe, F., Botzler, C. S., Douchin, D., Fukui, A., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Muraki, Y., Nagayama, T., Nishimoto, K., Ohnishi, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Collaboration, The MOA, Bolt, G., Bos, M., Christie, G. W., DePoy, D. L., Drummond, J., Gal-Yam, A., Gaudi, B. S., Gorbikov, E., Higgins, D., Janczak, K. -H. Hwang J., Kaspi, S., Lee, C. -U., Koo, J. -R., lowski, S. Koz, Lee, Y., Mallia, F., Maury, A., Maoz, D., McCormick, J., Monard, L. A. G., Moorhouse, D., Mu~noz, J. A., Natusch, T., Ofek, E. O., Pogge, R. W., Polishook, D., Santallo, R., Shporer, A., Spector, O., Thornley, G., Collaboration, The Micro FUN, Allan, A., Bramich, D. M., Horne, K., Kains, N., Steele, I., Collaboration, The RoboNet, Bozza, V., Burgdorf, M. J., Novati, S. Calchi, Dominik, M., Dreizler, S., Glitrup, M., Hessman, F. V., Hinse, T. C., Jorgensen, U. G., Liebig, C., Maier, G., Mathiasen, M., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Southworth, J., Surdej, J., Wambsganss, J., Zimmer, F., Consortium, The MiNDSTEp, Batista, V., Beaulieu, J. P., Brillant, S., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Greenhill, J., Kubas, D., Menzies, J., and Collaboration, The PLANET

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Planetary system, Mass ratio, Gravitational microlensing, Light curve, 01 natural sciences, Einstein radius, Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, Planet, Saturn, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010306 general physics, 010303 astronomy & astrophysics, Planetary mass, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting a K or M-dwarf star in the inner Galactic disk or Galactic bulge. The high cadence observations of the MOA-II survey discovered this microlensing event and enabled its identification as a high magnification event approximately 24 hours prior to peak magnification. As a result, the planetary signal at the peak of this light curve was observed by 20 different telescopes, which is the largest number of telescopes to contribute to a planetary discovery to date. The microlensing model for this event indicates a planet-star mass ratio of q = (3.95 +/- 0.02) x 10^{-4} and a separation of d = 0.97537 +/- 0.00007 in units of the Einstein radius. A Bayesian analysis based on the measured Einstein radius crossing time, t_E, and angular Einstein radius, \theta_E, along with a standard Galactic model indicates a host star mass of M_L = 0.38^{+0.34}_{-0.18} M_{Sun} and a planet mass of M_p = 50^{+44}_{-24} M_{Earth}, which is half the mass of Saturn. This analysis also yields a planet-star three-dimensional separation of a = 2.4^{+1.2}_{-0.6} AU and a distance to the planetary system of D_L = 6.1^{+1.1}_{-1.2} kpc. This separation is ~ 2 times the distance of the snow line, a separation similar to most of the other planets discovered by microlensing., Comment: accepted to ApJ, 28 pages, 6 figures, 3 tables

Published
2011

19. MOA-2009-BLG-387Lb: A massive planet orbiting an M dwarf

Author

Batista, V., Gould, A., Dieters, S., Dong, S., Bond, I., Beaulieu, J. P., Maoz, D., Monard, B., Christie, G. W., Mccormick, J., Albrow, M. D., Horne, K., Tsapras, Y., Burgdorf, M. J., Calchi Novati, S., Skottfelt, J., Caldwell, J., Kozłowski, S., Kubas, D., Gaudi, B. S., Han, C., Bennett, D. P., An, J., Abe, F., Botzler, C. S., Douchin, D., Freeman, M., Fukui, A., Furusawa, K., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Makita, B. S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Perrott, Y. C., Rattenbury, N., Saito, T. o., Sullivan, D. J., Sumi, T., Sweatman, W. L., Tristram, P. J., von Seggern, E., Yock, P. C. M., Brillant, S., Calitz, J. J., Cassan, A., Cole, A., Cook, K., Coutures, C., Dominis Prester, D., Donatowicz, J., Greenhill, J., Hoffman, M., Jablonski, F., Kane, S. R., Kains, N., Marquette, J. B., Martin, R., Martioli, E., Meintjes, P., Menzies, J., Pedretti, E., Pollard, K., Sahu, K. C., Vinter, C., Wambsganss, J., Watson, R., Williams, A., Zub, M., Allen, W., Bolt, G., Bos, M., Depoy, D. L., Drummond, J., Eastman, J. D., Gal Yam, A., Gorbikov, E., Higgins, D., Janczak, J., Kaspi, S., Lee, C. U., Mallia, F., Maury, A., Monard, L. A. G., Moorhouse, D., Morgan, N., Natusch, T., Ofek, E. O., Park, B. G., Pogge, R. W., Polishook, D., Santallo, R., Shporer, A., Spector, O., Thornley, G., Yee, J. C., Bozza, Valerio, Browne, P., Dominik, M., Dreizler, S., Finet, F., Glitrup, M., Grundahl, F., Harpsøe, K., Hessman, F. V., Hinse, T. C., Hundertmark, M., Jørgensen, U. G., Liebig, C., Maier, G., Mancini, L., Mathiasen, M., Rahvar, S., Ricci, D., Scarpetta, Gaetano, Southworth, J., Surdej, J., Zimmer, F., Allan, A., Bramich, D. M., Snodgrass, C., Steele, I. A., and Street, R. A.

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Mass ratio, Gravitational microlensing, 01 natural sciences, Einstein radius, Jupiter, Settore FIS/05 - Astronomia e Astrofisica, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Orbital motion, High Energy Physics::Experiment, gravitational lensing, micro methods, data analysis, planets, satellites, detection, methods, numerical, instrumentation, adaptive optics, photometers, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Planetary mass, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of a planet with a high planet-to-star mass ratio in the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over a 12-day interval, one of the longest for any planetary event. The host is an M dwarf, with a mass in the range 0.07 M_sun < M_host < 0.49M_sun at 90% confidence. The planet-star mass ratio q = 0.0132 +- 0.003 has been measured extremely well, so at the best-estimated host mass, the planet mass is m_p = 2.6 Jupiter masses for the median host mass, M = 0.19 M_sun. The host mass is determined from two "higher order" microlensing parameters. One of these, the angular Einstein radius ��_E = 0.31 +- 0.03 mas, is very well measured, but the other (the microlens parallax ��_E, which is due to the Earth's orbital motion) is highly degenate with the orbital motion of the planet. We statistically resolve the degeneracy between Earth and planet orbital effects by imposing priors from a Galactic model that specifies the positions and velocities of lenses and sources and a Kepler model of orbits. The 90% confidence intervals for the distance, semi-major axis, and period of the planet are 3.5 kpc < D_L < 7.9 kpc, 1.1 AU < a < 2.7AU, and 3.8 yr < P < 7.6 yr, respectively., 20 pages including 8 figures. A&A 529 102 (2011)

Published
2011
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20. OGLE-2009-BLG-092/MOA-2009-BLG-137: A Dramatic Repeating Event with the Second Perturbation Predicted by Real-time Analysis

Author

Ryu, Y. H., Han, C., Hwang, K. H., Street, R., Udalski, A., Sumi, T., Fukui, A., Beaulieu, J. P., Gould, A., Dominik, M., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nishimoto, K., Ohnishi, K., Perrott, Y. C., Rattenbury, N., Saito, T. o., Skuljan, L., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Szymański, M. K., Kubiak, M., Pietrzyński, G., Poleski, R., Soszyński, I., Szewczyk, O., Wyrzykowski, Ł., Ulaczyk, K., Bos, M., Christie, G. W., Depoy, D. L., Gal Yam, A., Gaudi, B. S., Kaspi, S., Lee, C. U., Maoz, D., Mccormick, J., Monard, B., Moorhouse, D., Pogge, R. W., Polishook, D., Shvartzvald, Y., Shporer, A., Thornley, G., Yee, J. C., Albrow, M. D., Batista, V., Brillant, S., Cassan, A., Cole, A., Corrales, E., Coutures, C. h., Dieters, S., Fouque, P., Greenhill, J., Menzies, J., Allan, A., Bramich, D. M., Browne, P., Horne, K., Kains, N., Snodgrass46, C., Steele, I., Tsapras, Y., Bozza, Valerio, Burgdorf, M. J., CALCHI NOVATI, Sebastiano, Dreizler, S., Finet, F., Glitrup, M., Grundahl, F., Harpsøe, K., Hessman, F. V., Hinse, T. C., Hundertmark, M., Jørgensen, U. G., Liebig, C., Maier, G., Mancini, Luigi, Mathiasen, M., Rahvar, S., Ricci, D., Scarpetta, Gaetano, Skottfelt, J., Surdej, J., Southworth, J., Wambsganss, J., and Zimmer, F.

Subjects
Physics, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Binary number, Perturbation (astronomy), Astronomy and Astrophysics, Astrophysics, Light curve, Gravitational microlensing, 01 natural sciences, Stars, Settore FIS/05 - Astronomia e Astrofisica, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Bulge, 0103 physical sciences, Orbital motion, Real time analysis, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract

We report the result of the analysis of a dramatic repeating gravitational microlensing event OGLE-2009-BLG-092/MOA-2009-BLG-137, for which the light curve is characterized by two distinct peaks with perturbations near both peaks. We find that the event is produced by the passage of the source trajectory over the central perturbation regions associated with the individual components of a wide-separation binary. The event is special in the sense that the second perturbation, occurring $\sim 100$ days after the first, was predicted by the real-time analysis conducted after the first peak, demonstrating that real-time modeling can be routinely done for binary and planetary events. With the data obtained from follow-up observations covering the second peak, we are able to uniquely determine the physical parameters of the lens system. We find that the event occurred on a bulge clump giant and it was produced by a binary lens composed of a K and M-type main-sequence stars. The estimated masses of the binary components are $M_1=0.69 \pm 0.11\ M_\odot$ and $M_2=0.36\pm 0.06\ M_\odot$, respectively, and they are separated in projection by $r_\perp=10.9\pm 1.3\ {\rm AU}$. The measured distance to the lens is $D_{\rm L}=5.6 \pm 0.7\ {\rm kpc}$. We also detect the orbital motion of the lens system., 18 pages, 5 figures, 1 table

Published
2010

21. A Cold Neptune-Mass Planet OGLE-2007-BLG-368Lb: Cold Neptunes Are Common

Author

Sumi, T., Bennett, D. P., Bond, I. A., Udalski, A., Batista, V., Dominik, M., Fouqu��, P., Kubas, D., Gould, A., Macintosh, B., Cook, K., Dong, S., Skuljan, L., Cassan, A., Collaboration, The MOA, Abe, F., Botzler, C. S., Fukui, A., Furusawa, K., Hearnshaw, J. B., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nagayama, T., Ohnishi, K., Okumura, T., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Sullivan, D. J., Sweatman, W. L., Yock, P. C. M., Collaboration, The PLANET, Beaulieu, J. P., Cole, A., Coutures, Ch., Duran, M. F., Greenhill, J., Jablonski, F., Marboeuf, U., Martioli, E., Pedretti, E., Pejcha, O., Rojo, P., Albrow, M. D., Brillant, S., Bode, M., Bramich, D. M., Burgdorf, M. J., Caldwell, J. A. R., Calitz, H., Corrales, E., Dieters, S., Prester, D. Dominis, Donatowicz, J., Hill, K., Hoffman, M., Horne, K., J, U. G., Kains, N., Kane, S., Marquette, J. B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Sahu, K. C., Snodgrass, C., Steele, I., Street, R., Tsapras, Y., Wambsganss, J., Williams, A., Zub, M., Collaboration, The OGLE, Szyma, M. K., Kubiak, M., Pietrzy, G., Soszy, I., Szewczyk, O., Ulaczyk, K., Collaboration, The microFUN, Allen, W., Christie, G. W., DePoy, D. L., Gaudi, B. S., Han, C., Janczak, J., Lee, C. -U., McCormick, J., Mallia, F., Monard, B., Natusch, T., Park, B. -G., Pogge, R. W., Santallo, R., Solar-Terrestrial Environment Laboratory [Nagoya] (STEL), Nagoya University, University of Notre Dame [Indiana] (UND), Massey University, Astronomical Observatory [Warsaw], Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), SUPA School of Physics and Astronomy [University of St Andrews], University of St Andrews [Scotland]-Scottish Universities Physics Alliance (SUPA), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Astronomische Rechen-Institut [Heidelberg] (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg] = Heidelberg University-Universität Heidelberg [Heidelberg] = Heidelberg University, Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Instituto Nacional de Pesquisas Espaciais (INPE), Ministério da Ciência, Tecnologia e Inovação, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)

Subjects
Physics, gravitational lensing: micro, planetary systems, Earth and Planetary Astrophysics (astro-ph.EP), Stellar mass, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Gas giant, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Mass ratio, Light curve, Gravitational microlensing, 01 natural sciences, Exoplanet, Space and Planetary Science, Neptune, Planet, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with a planet-star mass ratio of q=[9.5 +/- 2.1] x 10^{-5} via gravitational microlensing. The planetary deviation was detected in real-time thanks to the high cadence of the MOA survey, real-time light curve monitoring and intensive follow-up observations. A Bayesian analysis returns the stellar mass and distance at M_l = 0.64_{-0.26}^{+0.21} M_\sun and D_l = 5.9_{-1.4}^{+0.9} kpc, respectively, so the mass and separation of the planet are M_p = 20_{-8}^{+7} M_\oplus and a = 3.3_{-0.8}^{+1.4} AU, respectively. This discovery adds another cold Neptune-mass planet to the planetary sample discovered by microlensing, which now comprise four cold Neptune/Super-Earths, five gas giant planets, and another sub-Saturn mass planet whose nature is unclear. The discovery of these ten cold exoplanets by the microlensing method implies that the mass ratio function of cold exoplanets scales as dN_{\rm pl}/d\log q \propto q^{-0.7 +/- 0.2} with a 95% confidence level upper limit of n < -0.35 (where dN_{\rm pl}/d\log q \propto q^n). As microlensing is most sensitive to planets beyond the snow-line, this implies that Neptune-mass planets are at least three times more common than Jupiters in this region at the 95% confidence level., 39 pages, 10 figures, accepted for publication in ApJ

Published
2009
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22. A NEW TYPE OF AMBIGUITY IN THE PLANET AND BINARY INTERPRETATIONS OF CENTRAL PERTURBATIONS OF HIGH-MAGNIFICATION GRAVITATIONAL MICROLENSING EVENTS

Author

Choi, J.-Y, Shin, I.-G, Han, C., Udalski, A., Sumi, T., Gould, A., Bozza, V., Dominik, M., Fouque´, P., Horne, K., Szyman´ski, M. K., Kubiak, M., Soszyn´ski, I., Pietrzyn´ski, G., Poleski, R., Ulaczyk, K., Pietrukowicz, P., Kozłowski, S., Skowron, J., Wyrzykowski, Ł., OGLE Collaboration, Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Itow, Y., Kobara, S., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohmori, K., Ohnishi, K., Rattenbury, N. J., Saito, To, Sullivan, D. J., Suzuki, D., Suzuki, K., Sweatman, W. L., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., MOA Collaboration, Bramich, D. M., Snodgrass, C., Steele, I. A., Street, R. A., Tsapras, Y., RoboNet Collaboration, Alsubai, K. A., Browne, P., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Dreizler, S., Fang, X.-S, Grundahl, F., Gu, C.-H, Hardis, S., Harpsøe, K., Hinse, T. C., Hornstrup, Allan, Hundertmark, M., Jessen-Hansen, J., Jørgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M., Lunkkvist, M., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Almeida, L. A., Batista, V., Christie, G., DePoy, D. L., Dong, Subo, Gaudi, B. S., Henderson, C., Jablonski, F., Lee, C.-U, McCormick, J., McGregor, D., Moorhouse, D., Natusch, T., Ngan, H., Pogge, R. W., Tan, T.-G, Thornley, G., Yee, J. C., Albrow, M. D., Bachelet, E., Beaulieu, J.-P, Brillant, S., Cassan, A., Cole, A. A., Corrales, E., Coutures, C., Dieters, S., Dominis Prester, D., Donatowicz, J., Greenhill, J., Kubas, D., Marquette, J.-B, Menzies, J. W., Sahu, K. C., and Zub, M.

Subjects
media_common.quotation_subject, FOS: Physical sciences, Binary number, Perturbation (astronomy), gravitational lensing: micro, Astrophysics, Gravitational microlensing, 01 natural sciences, Galaxy: bulge, Settore FIS/05 - Astronomia e Astrofisica, Planet, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), media_common, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Binary Independence Model, Astronomy and Astrophysics, Ambiguity, Light curve, Galaxy: bulge, gravitational lensing: micro, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Caustic (optics), Astrophysics - Earth and Planetary Astrophysics
Abstract

High-magnification microlensing events provide an important channel to detect planets. Perturbations near the peak of a high-magnification event can be produced either by a planet or a binary companion. It is known that central perturbations induced by both types of companions can be generally distinguished due to the basically different magnification pattern around caustics. In this paper, we present a case of central perturbations for which it is difficult to distinguish the planetary and binary interpretations. The peak of a lensing light curve affected by this perturbation appears to be blunt and flat. For a planetary case, this perturbation occurs when the source trajectory passes the negative perturbation region behind the back end of an arrowhead-shaped central caustic. For a binary case, a similar perturbation occurs for a source trajectory passing through the negative perturbation region between two cusps of an astroid-shaped caustic. We demonstrate the degeneracy for 2 high-magnification events of OGLE-2011-BLG-0526 and OGLE-2011-BLG-0950/MOA-2011-BLG-336. For OGLE-2011-BLG-0526, the $\chi^2$ difference between the planetary and binary model is $\sim$ 3, implying that the degeneracy is very severe. For OGLE-2011-BLG-0950/MOA-2011-BLG-336, the stellar binary model is formally excluded with $\Delta \chi^2 \sim$ 105 and the planetary model is preferred. However, it is difficult to claim a planet discovery because systematic residuals of data from the planetary model are larger than the difference between the planetary and binary models. Considering that 2 events observed during a single season suffer from such a degeneracy, it is expected that central perturbations experiencing this type of degeneracy is common., Comment: 8 pages, 8 figures

Published
2012

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