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Your search keyword '"Corrales, E."' showing total 429 results
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429 results on '"Corrales, E."'

2. Prevalence, risk factors and evolution of diabetes mellitus after treatment in primary aldosteronism. Results from the SPAIN-ALDO registry

Author

Araujo-Castro, M., Paja Fano, M., Pla Peris, B., González Boillos, M., Pascual-Corrales, E., García Cano, A. M., Parra Ramírez, P., Martín Rojas-Marcos, P., Ruiz-Sanchez, J. G., Vicente Delgado, A., Gómez Hoyos, E., Ferreira, R., García Sanz, I., Recasens Sala, M., Barahona San Millan, R., Picón César, M. J., Díaz Guardiola, P., Perdomo, C. M., Manjón Miguélez, L., García Centeno, R., Percovich, J. C., Rebollo Román, Á., Gracia Gimeno, P., Robles Lázaro, C., Morales-Ruiz, M., Calatayud Gutiérrez, M., Furio Collao, S. A., Meneses, D., Sampedro Nuñez, M. A., Escudero Quesada, V., Mena Ribas, E., Sanmartín Sánchez, A., Gonzalvo Diaz, C., Lamas, C., Guerrero-Vázquez, R., del Castillo Tous, M., Serrano Gotarredona, J., Michalopoulou Alevras, T., Moya Mateo, E. M., and Hanzu, F. A.

Published
2023
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10. Protocol for presurgical and anesthetic management of pheochromocytomas and sympathetic paragangliomas: a multidisciplinary approach

Author

Araujo-Castro, M., Pascual-Corrales, E., Nattero Chavez, L., Martínez Lorca, A., Alonso-Gordoa, T., Molina-Cerrillo, J., Lorca Álvaro, J., Mínguez Ojeda, C., Redondo López, S., Barberá Durbán, R., Polo López, R., Moreno Mata, N., Caballero Silva, U., Pian, H., Ruz-Caracuel, I., Sanjuanbenito Dehesa, A., Gómez Dos Santos, V., and Serrano Romero, A. B.

Published
2021
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11. Socioeconomic Development in Eastern Cuba through Family Farming of Mulberry Plants: Biotechnological Application

Author

Rodríguez, Sergio, primary, Silva, J. J., additional, Werbrouck, S., additional, Pérez, J., additional, Espinosa, A., additional, Fonseca, Y., additional, Bahí, M., additional, Gómez, R., additional, Negrín, M., additional, Corrales, E., additional, Antúnez, G., additional, Soler, Y., additional, Conci, M. C., additional, Moine, B., additional, Tamagno, V., additional, Romero, A., additional, and García, R., additional

Published
2021
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29. OGLE-2011-BLG-0265Lb: a Jovian Microlensing Planet Orbiting an M Dwarf

Author

Skowron, J., Shin, I. -G., Udalski, A., Han, C., Sumi, T., Shvartzvald, Y., Gould, A., Dominis-Prester, D., Street, R. A., Jørgensen, U. G., Bennett, D. P., Bozza, V., Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Kozłowski, S., Pietrukowicz, P., Ulaczyk, K., Wyrzykowski, Ł., Abe, F., Bhattacharya, A., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Fukunaga, D., Itow, Y., Ling, C. H., Koshimoto, N., Masuda, K., Matsubara, Y., Muraki, Y., Namba, S., Ohnishi, K., Philpott, L. C., Rattenbury, N., Saito, T., Sullivan, D. J., Suzuki, D., Tristram, P. J., Yock, P. C. M., Maoz, D., Kaspi, S., Friedman, M., Almeida, L. A., Batista, V., Christie, G., Choi, J. -Y., DePoy, D. L., Gaudi, B. S., Henderson, C., Hwang, K. -H., Jablonski, F., Jung, Y. K., Lee, C. -U., McCormick, J., Natusch, T., Ngan, H., Park, H., Pogge, R. W., Yee, J., Albrow, M. D., Bachelet, E., Beaulieu, J. -P., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Donatowicz, J., Fouqué, P., Greenhill, J., Kains, N., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Menzies, J., Pollard, K. R., Ranc, C., Sahu, K. C., Wambsganss, J., Williams, A., Wouters, D., Tsapras, Y., Bramich, D. M., Horne, K., Hundertmark, M., Snodgrass, C., Steele, I. A., Alsubai, K. A., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dominik, M., Dreizler, S., Fang, X. -S., Gu, C. -H., Hardis, Harpsøe, K., Hessman, F. V., Hinse, T. C., Hornstrup, A., Jessen-Hansen, J., Kerins, E., Liebig, C., Lund, M., Lundkvist, M., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Southworth, J., Surdej, J., Tregloan-Reed, J., and Wertz, O.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of a Jupiter-mass planet orbiting an M-dwarf star that gave rise to the microlensing event OGLE-2011-BLG-0265. Such a system is very rare among known planetary systems and thus the discovery is important for theoretical studies of planetary formation and evolution. High-cadence temporal coverage of the planetary signal combined with extended observations throughout the event allows us to accurately model the observed light curve. The final microlensing solution remains, however, degenerate yielding two possible configurations of the planet and the host star. In the case of the preferred solution, the mass of the planet is $M_{\rm p} = 0.9\pm 0.3\ M_{\rm J}$, and the planet is orbiting a star with a mass $M = 0.22\pm 0.06\ M_\odot$. The second possible configuration (2$\sigma$ away) consists of a planet with $M_{\rm p}=0.6\pm 0.3\ M_{\rm J}$ and host star with $M=0.14\pm 0.06\ M_\odot$. The system is located in the Galactic disk 3 -- 4 kpc towards the Galactic bulge. In both cases, with an orbit size of 1.5 -- 2.0 AU, the planet is a "cold Jupiter" -- located well beyond the "snow line" of the host star. Currently available data make the secure selection of the correct solution difficult, but there are prospects for lifting the degeneracy with additional follow-up observations in the future, when the lens and source star separate., Comment: 10 pages, 2 tables, 5 figures. Accepted in ApJ

Published
2014
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31. A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge

Author

Bennett, D. P., Batista, V., Bond, I. A., Bennett, C. S., Suzuki, D., Beaulieu, J. -P., Udalski, A., Donatowicz, J., Abe, F., Botzler, C. S., Freeman, M., Fukunaga, D., Fukui, A., Itow, Y., Koshimoto, N., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Namba, S., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sumi, T., Sweatman, W. L., Tristram, P. J., Tsurumi, N., Wada, K., Yock, P. C. M., Albrow, M. D., Bachelet, E., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A. A., Corrales, E., Coutures, C., Dieters, S., Prester, D. Dominis, Fouque, P., Greenhill, J., Horne, K., Koo, J. -R., Kubas, D., Marquette, J. -B., Martin, R., Menzies, J. W., Sahu, K. C., Wambsganss, J., Williams, A., Choi, M. Zub J. Y., DePoy, D. L., Dong, Subo, Gaudi, B. S., Gould, A., Han, C., Henderson, C. B., McGregor, D., Lee, C. -U., Pogge, R. W., Shin, I. -G., Yee, J. C., Szymaski, M. K., Skowron, J., Poleski, R., Kozowski, S., Wyrzykowski, L., Kubiak, M., Pietrukowicz, P., Pietrzyski, G., Soszyski, I., Ulaczyk, K., Tsapras, Y., Street, R. A., Dominik, M., Bramich, D. M., Browne, P., Hundertmark, M., Kains, N., Snodgrass, C., Steele, I. A., Dekany, I., Gonzalez, O. A., Heyrovsky, D., Kandori, R., Kerins, E., Lucas, P. W., Minniti, D., Nagayama, T., Rejkuba, M., Robin, A. C., and Saito, R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the first microlensing candidate for a free-floating exoplanet-exomoon system, MOA-2011-BLG-262, with a primary lens mass of M_host ~ 4 Jupiter masses hosting a sub-Earth mass moon. The data are well fit by this exomoon model, but an alternate star+planet model fits the data almost as well. Nevertheless, these results indicate the potential of microlensing to detect exomoons, albeit ones that are different from the giant planet moons in our solar system. The argument for an exomoon hinges on the system being relatively close to the Sun. The data constrain the product M pi_rel, where M is the lens system mass and pi_rel is the lens-source relative parallax. If the lens system is nearby (large pi_rel), then M is small (a few Jupiter masses) and the companion is a sub-Earth-mass exomoon. The best-fit solution has a large lens-source relative proper motion, mu_rel = 19.6 +- 1.6 mas/yr, which would rule out a distant lens system unless the source star has an unusually high proper motion. However, data from the OGLE collaboration nearly rule out a high source proper motion, so the exoplanet+exomoon model is the favored interpretation for the best fit model. However, the alternate solution has a lower proper motion, which is compatible with a distant (so stellar) host. A Bayesian analysis does not favor the exoplanet+exomoon interpretation, so Occam's razor favors a lens system in the bulge with host and companion masses of M_host = 0.12 (+0.19 -0.06) M_solar and m_comp = 18 (+28 -100 M_earth, at a projected separation of a_perp ~ 0.84 AU. The existence of this degeneracy is an unlucky accident, so current microlensing experiments are in principle sensitive to exomoons. In some circumstances, it will be possible to definitively establish the low mass of such lens systems through the microlensing parallax effect. Future experiments will be sensitive to less extreme exomoons., Comment: 32 pages with 9 included figures

Published
2013
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32. A Super-Jupiter orbiting a late-type star: A refined analysis of microlensing event OGLE-2012-BLG-0406

Author

Tsapras, Y., Choi, J. -Y., Street, R. A., Han, C., Bozza, V., Gould, A., Dominik, M., Beaulieu, J. -P., Udalski, A., Jørgensen, U. G., Sumi, T., Bramich, D. M., Browne, P., Horne, K., Hundertmark, M., Ipatov, S., Kains, N., Snodgrass, C., Steele, I. A., Alsubai, K. A., Andersen, J. M., Novati, S. Calchi, Damerdji, Y., Diehl, C., Elyiv, A., Giannini, E., Hardis, S., Harpsøe, K., Hinse, T. C., Juncher, D., Kerins, E., Korhonen, H., Liebig, C., Mancini, L., Mathiasen, M., Penny, M. T., Rabus, M., Rahvar, S., Scarpetta, G., Skottfelt, J., Southworth, J., Surdej, J., Tregloan-Reed, J., Vilela, C., Wambsganss, J., Skowron, J., Poleski, R., Kozłowski, S., Wyrzykowski, Łukasz, Szymański, M. K., Kubiak, M., Pietrukowicz, P., Pietrzyński, G., Soszyński, I., Ulaczyk, K., Albrow, M. D., Bachelet, E., Barry, R., Batista, V., Bhattacharya, A., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Kane, S. R., Kubas, D., Marquette, J. -B., Menzies, J., P`ere, C., Pollard, K. R., Wouters, D., Christie, G., DePoy, D. L., Dong, S., Drummond, J., Gaudi, B. S., Henderson, C. B., Hwang, K. H., Jung, Y. K., Kavka, A., Koo, J. -R., Lee, C. -U., Maoz, D., Monard, L. A. G., Natusch, T., Ngan, H., Park, H., Pogge, R. W., Porritt, I., Shin, I. -G., Shvartzvald, Y., Tan, T. G., Yee, J. C., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Fukunaga, D., Itow, Y., Koshimoto, N., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Namba, S., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sweatman, W. L., Suzuki, D., Tristram, P. J., Tsurumi, N., Wada, K., Yamai, N., and Yonehara, P. C. M. Yock A.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present a detailed analysis of survey and follow-up observations of microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive coverage of the lightcurve, especially the perturbation part, allowed us to accurately measure the parallax effect and lens orbital motion. Combining our measurement of the lens parallax with the angular Einstein radius determined from finite-source effects, we estimate the physical parameters of the lens system. We find that the event was caused by a $2.73\pm 0.43\ M_{\rm J}$ planet orbiting a $0.44\pm 0.07\ M_{\odot}$ early M-type star. The distance to the lens is $4.97\pm 0.29$\ kpc and the projected separation between the host star and its planet at the time of the event is $3.45\pm 0.26$ AU. We find that the additional coverage provided by follow-up observations, especially during the planetary perturbation, leads to a more accurate determination of the physical parameters of the lens., Comment: 9 pages, 4 figures, accepted by ApJ

Published
2013
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33. 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., and Zub, M.

Subjects
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
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34. Interpretation of a Short-Term Anomaly in the Gravitational Microlensing Event MOA-2012-BLG-486

Author

Hwang, K. -H., Choi, J. -Y., Bond, I. A., Sumi, T., Han, C., Gaudi, B. S., Gould, A., Bozza, V., Beaulieu, J. -P., Tsapras, Y., Abe, F., Bennett, D. P., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Fukunaga, D., Harris, P., Itow, Y., Koshimoto, N., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Namba, S., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sweatman, W. L., Suzuki, D., Tristram, P. J., Wada, K., Yamai, N., Yock, P. C. M., Yonehara, A., de Almeida, L. Andrade, DePoy, D. L., Dong, Subo, Jablonski, F., Jung, Y. K., Kavka, A., Lee, C. -U., Park, H., Pogge, R. W., Shin, I. -G., Yee, J. C., Albrow, M. D., Bachelet, E., Batista, V., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Jørgensen, U. G., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Williams, A., Wouters, D., Bramich, D. M., Dominik, M., Horne, K., Browne, P., Hundertmark, M., Ipatov, S., Kains, N., Snodgrass, C., Steele, I. A., and Street, R. A.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

A planetary microlensing signal is generally characterized by a short-term perturbation to the standard single lensing light curve. A subset of binary-source events can produce perturbations that mimic planetary signals, thereby introducing an ambiguity between the planetary and binary-source interpretations. In this paper, we present analysis of the microlensing event MOA-2012-BLG-486, for which the light curve exhibits a short-lived perturbation. Routine modeling not considering data taken in different passbands yields a best-fit planetary model that is slightly preferred over the best-fit binary-source model. However, when allowed for a change in the color during the perturbation, we find that the binary-source model yields a significantly better fit and thus the degeneracy is clearly resolved. This event not only signifies the importance of considering various interpretations of short-term anomalies, but also demonstrates the importance of multi-band data for checking the possibility of false-positive planetary signals., Comment: 5 pages, 4 figures and ApJ submitted

Published
2013
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35. A Giant Planet beyond the Snow Line in Microlensing Event OGLE-2011-BLG-0251

Author

Kains, N., Street, R., Choi, J. -Y., Han, C., Udalski, A., Almeida, L. A., Jablonski, F., Tristram, P., Jorgensen, U. G., Szymanski, M. K., Kubiak, M., Pietrzynski, G., Soszynski, I., Poleski, R., Kozlowski, S., Pietrukowicz, P., Ulaczyk, K., Wyrzykowski, L., Skowron, J., Alsubai, K. A., Bozza, V., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dominik, M., Dreizler, S., Fang, X. -S., Grundahl, F., Gu, C. -H., Hardis, S., Harpsoe, K., Hessman, F. V., Hinse, T. C., Hornstrup, A., Hundertmark, M., Jessen-Hansen, J., Kerins, E., Liebig, C., Lund, M., Lundkvist, M., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Sahu, K. C., Scarpetta, G., Skottfelt, J., Snodgrass, C., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Bajek, D., Bramich, D. M., Horne, K., Ipatov, S., Steele, I. A., Tsapras, Y., Abe, F., Bennett, D. P., 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., Saito, T., Sullivan, D. J., Sumi, T., Suzuki, D., Suzuki, K., Sweatman, W. L., Takino, S., Wada, K., Yock, P. C. M., Allen, W., Batista, V., Chung, S. -J., Christie, G., DePoy, D. L., Drummond, J., Gaudi, B. S., Gould, A., Henderson, C., Jung, Y. -K., Koo, J. -R., Lee, C. -U., McCormick, J., McGregor, D., Munoz, J. A., Natusch, T., Ngan, H., Park, H., Pogge, R. W., Shin, I. -G., Yee, J., Albrow, M. D., Bachelet, E., Beaulieu, J. -P., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouque, P., Greenhill, J., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Williams, A., Wouters, D., and Zub, M.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic Bulge. Based on detailed modelling of the observed light curve, we find that the lens is composed of two masses with a mass ratio q=1.9 x 10^-3. Thanks to our detection of higher-order effects on the light curve due to the Earth's orbital motion and the finite size of source, we are able to measure the mass and distance to the lens unambiguously. We find that the lens is made up of a planet of mass 0.53 +- 0.21,M_Jup orbiting an M dwarf host star with a mass of 0.26 +- 0.11 M_Sun. The planetary system is located at a distance of 2.57 +- 0.61 kpc towards the Galactic Centre. The projected separation of the planet from its host star is d=1.408 +- 0.019, in units of the Einstein radius, which corresponds to 2.72 +- 0.75 AU in physical units. We also identified a competitive model with similar planet and host star masses, but with a smaller orbital radius of 1.50 +- 0.50 AU. The planet is therefore located beyond the snow line of its host star, which we estimate to be around 1-1.5 AU., Comment: 12 pages, 7 figures, 3 tables; A&A in press

Published
2013
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36. MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary

Author

Street, R. A., Choi, J. -Y., Tsapras, Y., Han, C., Furusawa, K., Hundertmark, M., Gould, A., Sumi, T., Bond, I. A., Wouters, D., Zellem, R., Udalski, A., Snodgrass, C., Horne, K., Dominik, M., Browne, P., Kains, N., Bramich, D. M., Bajek, D., Steele, I. A., Ipatov, S., Abe, F., Bennett, D. P., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Harris, P., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagayama, T., Nishimaya, S., Ohnishi, K., Rattenbury, N., Saito, To., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Szymanski, M. K., Kubiak, M., Pietrzynski, G., Soszynski, I., Poleski, R., Ulaczyk, K., Wyrzykowski, L., Yee, J., Dong, S., Shin, I. -G., Lee, C. -U., Skowron, J., De Almeida, L. Andrade, DePoy, D. L., Gaudi, B. S., Hung, L. -W., Jablonski, F., Kaspi, S., Klein, N., Hwang, K. -H., Koo, J. -R., Maoz, D., Munoz, J. A., Pogge, R. W., Polishhook, D., Shporer, A., McCormick, J., Christie, G., Natusch, T., Allen, B., Drummond, J., Moorhouse, D., Thornley, G., Knowler, M., Bos, M., Bolt, G., Beaulieu, J. -P., Albrow, M. D., Batista, V., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouque, P., Bachelet, E., Greenhill, J., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Menzies, J., Pollard, K. R., Sahu, K. C., Wambsganss, J., Williams, A., Zub, M., Alsubai, K. A., Bozza, V., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Finet, F., Gerner, T., Hardis, S., Harpsoe, K., Hessman, F., Hinse, T. C., Jorgensen, U. G., 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., and Surdej, J.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010-03-18. This event was remarkable because the source was previously known to be photometrically variable. Analyzing the pre-event source lightcurve, we demonstrate that it is an irregular variable over time scales >200d. Its dereddened color, $(V-I)_{S,0}$, is 1.221$\pm$0.051mag and from our lens model we derive a source radius of 14.7$\pm$1.3 $R_{\odot}$, suggesting that it is a red giant star. We initially explored a number of purely microlensing models for the event but found a residual gradient in the data taken prior to and after the event. This is likely to be due to the variability of the source rather than part of the lensing event, so we incorporated a slope parameter in our model in order to derive the true parameters of the lensing system. We find that the lensing system has a mass ratio of q=0.0654$\pm$0.0006. The Einstein crossing time of the event, $T_{\rm{E}}=44.3$\pm$0.1d, was sufficiently long that the lightcurve exhibited parallax effects. In addition, the source trajectory relative to the large caustic structure allowed the orbital motion of the lens system to be detected. Combining the parallax with the Einstein radius, we were able to derive the distance to the lens, $D_L$=2.8$\pm$0.4kpc, and the masses of the lensing objects. The primary of the lens is an M-dwarf with $M_{L,p}$=0.16$\pm0.03M_{\odot}$ while the companion has $M_{L,s}$=11.0$\pm2.0M_{\rm{J}}$ putting it in the boundary zone between planets and brown dwarfs., Comment: 24 pages, 8 figures, best viewed in colour, accepted by ApJ

Published
2012
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37. MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detection

Author

Yee, J. C., Hung, L. -W., Bond, I. A., Allen, W., Monard, L. A. G., Albrow, M. D., Fouque, P., Dominik, M., Tsapras, Y., Udalski, A., Gould, A., Zellem, R., Bos, M., Christie, G. W., DePoy, D. L., Dong, Subo, Drummond, J., Gaudi, B. S., Gorbikov, E., Han, C., Kaspi, S., Klein, N., Lee, C. -U., Maoz, D., McCormick, J., Moorhouse, D., Natusch, T., Nola, M., Park, B. -G., Pogge, R. W., Polishook, D., Shporer, A., Shvartzvald, Y., Skowron, J., Thornley, G., Abe, F., Bennett, D. P., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Harris, P., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sumi, T., 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., Bachelet, E., Batista, V., Beatty, T. G., Beaulieu, J. -P., Bennett, C. S., Bowens-Rubin, R., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A. A., Corrales, E., Coutures, C., Dieters, S., Prester, D. Dominis, Donatowicz, J., Greenhill, J., Henderson, C. B., Kubas, D., Marquette, J. -B., Martin, R., Menzies, J. W., Shappee, B., Williams, A., Wouters, D., van Saders, J., Zub, M., Street, R. A., Horne, K., Bramich, D. M., Steele, I. A., Alsubai, K. A., Bozza, V., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Finet, F., Gerner, T., Hardis, S., Harpsoe, K., Hessman, F. V., Hinse, T. C., Hundertmark, M., Jorgensen, U. G., Kains, N., Kerins, E., Liebig, C., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Sahu, K. C., Scarpetta, G., Schafer, S., Schonebeck, F., Snodgrass, C., Southworth, J., Surdej, J., and Wambsgans, J.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We analyze MOA-2010-BLG-311, a high magnification (A_max>600) microlensing event with complete data coverage over the peak, making it very sensitive to planetary signals. We fit this event with both a point lens and a 2-body lens model and find that the 2-body lens model is a better fit but with only Delta chi^2~80. The preferred mass ratio between the lens star and its companion is $q=10^(-3.7+/-0.1), placing the candidate companion in the planetary regime. Despite the formal significance of the planet, we show that because of systematics in the data the evidence for a planetary companion to the lens is too tenuous to claim a secure detection. When combined with analyses of other high-magnification events, this event helps empirically define the threshold for reliable planet detection in high-magnification events, which remains an open question., Comment: 29 pages, 6 Figures, 3 Tables. For a brief video presentation on this paper, please see http://www.youtube.com/user/OSUAstronomy 10/25/2012 - Updated author list. Replaced 10/10/13 to reflect the version published in ApJ

Published
2012
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38. MOA-2010-BLG-523: 'Failed Planet' = RS CVn Star

Author

Gould, A., Yee, J. C., Bond, I. A., Udalski, A., Han, C., Jorgensen, U. G., Greenhill, J., Tsapras, Y., Pinsonneault, M. H., Bensby, T., Allen, W., Almeida, L. A., Bos, M., Christie, G. W., DePoy, D. L., Dong, Subo, Gaudi, B. S., Hung, L. -W., Jablonski, F., Lee, C. -U., McCormick, J., Moorhouse, D., Munoz, J. A., Natusch, T., Nola, M., Pogge, R. W., Skowron, J., Thornley, G., Abe, F., Bennett, D. P., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Harris, P., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sumi, T., 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., 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., Hessman, F. V., Hinse, T. C., Hundertmark, M., Kains, N., Kerins, E., Liebig, C., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Sahu, K. C., Scarpetta, G., Schafer, S., Schonebeck, F., Snodgrass, C., Southworth, J., Surdej, J., Wambsganss, J., Street, R. A., Horne, K., Bramich, D. M., Steele, I. A., Albrow, M. D., Bachelet, E., Batista, V., Beatty, T. G., Beaulieu, J. -P., Bennett, C. S., Bowens-Rubin, R., Brillant, S., Caldwell, J. A. R., Cassan, A., Cole, A. A., Corrales, E., Coutures, C., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouque, P., Henderson, C. B., Kubas, D., Marquette, J. -B, Martin, R., Menzies, J. W., Shappee, B., Williams, A., van Saders, J., and Zub, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing lightcurve near the peak of an Amax ~ 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spectrum taken near peak to demonstrate that this is an RS CVn variable, so that planetary microlensing is not required to explain the lightcurve deviations. This is the first spectroscopically confirmed RS CVn star discovered in the Galactic bulge., Comment: 29 pp, 6 figs, submitted to ApJ

Published
2012
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39. Microlensig 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., 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., 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., Bajek, D., Bramich, D. M., Browne, P., Horne, K., Ipatov, S., Snodgrass, C., Steele, I., Street, R., Alsubai, K. A., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Fang, X. -S., Grundahl, F., Gu, C. -H., Hardis, S., Harpsøe, K., Hinse, T. C., Hundertmark, M., Jessen-Hansen, J., Jørgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M., Lundkvist, M., Mancini, L., Mathiasen, M., Hornstrup, A., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., 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., Prester, D. Dominis, 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, C., and Zub, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics
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., Comment: 10 pages, 9 figures, 4 tables

Published
2012
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40. MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light

Author

Bachelet, E., Shin, I. -G., Han, C., Fouqué, P., Gould, A., Menzies, J. W., Beaulieu, J. -P., Bennett, D. P., Bond, I. A., Dong, Subo, Heyrovský, D., Marquette, J. B., Marshall, J., Skowron, J., Street, R. A., Sumi, T., Udalski, A., Abe, L., Agabi, K., Albrow, M. D., Allen, W., Bertin, E., Bos, M., Bramich, D. M., Chavez, J., Christie, G. W., Cole, A. A., Crouzet, N., Dieters, S., Dominik, M., Drummond, J., Greenhill, J., Guillot, T., Henderson, C. B., Hessman, F. V., Horne, K., Hundertmark, M., Johnson, J. A., Jørgensen, U. G., Kandori, R., Liebig, C., Mékarnia, D., McCormick, J., Moorhouse, D., Nagayama, T., Nataf, D., Natusch, T., Nishiyama, S., Rivet, J. -P., Sahu, K. C., Shvartzvald, Y., Thornley, G., Tomczak, A. R., Tsapras, Y., Yee, J. C., Batista, V., Bennett, C. S., Brillant, S., Caldwell, J. A. R., Cassan, A., Corrales, E., Coutures, C., Prester, D. Dominis, Donatowicz, J., Kubas, D., Martin, R., Williams, A., Zub, M., de Almeida, L. Andrade, DePoy, D. L., Gaudi, B. S., Hung, L. -W., Jablonski, F., Kaspi, S., Klein, N., Lee, C. -U., Lee, Y., Koo, J. -R., Maoz, D., Muñoz, J. A., Pogge, R. W., Polishook, D., Shporer, A., Abe, F., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Harris, P., Itow, Y., Kobara, S., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Ohmori, K., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Szymański, M. K., Soszyński, I., Kubiak, M., Poleski, R., Ulaczyk, K., Pietrzyński, G., Wyrzykowski, Ł., Kains, N., Snodgrass, C., Steele, I. A., Alsubai, K. A., Bozza, V., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Finet, F., Gerner, T., Hardis, S., Harpsøe, K., Hinse, T. C., Kerins, E., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Schäfer, S., Schönebeck, F., Southworth, J., Surdej, J., and Wambsganss, J.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA-2010-BLG-477. The measured planet-star mass ratio is $q=(2.181\pm0.004)\times 10^{-3}$ and the projected separation is $s=1.1228\pm0.0006$ in units of the Einstein radius. The angular Einstein radius is unusually large $\theta_{\rm E}=1.38\pm 0.11$ mas. Combining this measurement with constraints on the "microlens parallax" and the lens flux, we can only limit the host mass to the range $0.13

Published
2012
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41. 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., Fouqué, P., Horne, K., Szymański, M. K., Kubiak, M., Soszyński, I., Pietrzyński, 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., Bramich, D. M., Snodgrass, C., Steele, I. A., Street, R. A., Tsapras, Y., Alsubai, K. A., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Fang, X. -S., Grundahl, F., Gu, C. -H., Hardis, S., Harpsøe, K., Hinse, T. C., Hornstrup, A., 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., 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., Prester, D. Dominis, Donatowicz, J., Greenhill, J., Kubas, D., Marquette, J. -B., Menzies, J. W., Sahu, K. C., and Zub, M.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar 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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42. 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., Fouqué, P., Horne, K., Szymański, K., Kubiak, M., Soszyński, I., Pietrzyński, 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., Bramich, D. M., Snodgrass, C., Steele, I. A., Street, R. A., Tsapras, Y., Alsubai, K. A., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Fang, X. -S., Grundahl, F., Gu, C. -H., Hardis, S., Harpsøe, K., Hinse, T. C., Hornstrup, A., 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., 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., Prester, D. Dominis, Donatowicz, J., Greenhill, J., Kubas, D., Marquette, J. -B., Menzies, J. W., Sahu, K. C., and Zub, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics
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
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43. 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., Tan, T. -G. "TG", Thornley, G., Yee, J. C., 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., Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Kozłowski, S., Pietrukowicz, P., 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., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Kane, S. R., Menzies, J., Sahu, K. C., Wambsganss, J., Williams, A., Zub, M., Allan, A., Bramich, D. M., Browne, P., Clay, N., Fraser, S., Horne, K., Kains, N., Mottram, C., Snodgrass, C., Steele, I., Tsapras, Y., Alsubai, K. A., Bozza, V., Burgdorf, M. J., Novati, S. Calchi, 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, J., Surdej, J., Southworth, J., and Zimmer, F.

Subjects
Astrophysics - Solar and Stellar Astrophysics
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
2011
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44. 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., 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., Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Kozłowski, S., Pietrukowicz, P., 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., Prester, D. Dominis, 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, C., Zub, M., Allan, A., Browne, P., Horne, K., Snodgrass, C., Steele, I., Street, R., Tsapras, Y., Alsubai, K. A., Bozza, V., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Finet, F., Gerner, T., Glitrup, M., Grundahl, F., Hardis, S., Harpsøe, K., 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, J., Surdej, J., Southworth, J., and Zimmer, F.

Subjects
Astrophysics - Solar and Stellar Astrophysics
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
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45. OGLE-2005-BLG-018: Characterization of Full Physical and Orbital Parameters of a Gravitational Binary Lens

Author

Shin, I. -G., Udalski, A., Han, C., Gould, A., Dominik, M., Fouque, P., Kubiak, M., Szymanski, M. K., Pietrzynki, G., Soszynski, I., Ulaczyk, K., Wyrzykowski, L., DePoy, D. L., Dong, S., Gaudi, B. S., Lee, C. -U., Park, B. -G., Pogge, R. W., Albrow, M. D., Allan, A., Beaulieu, J. P., Bennett, D. P., Bode, M., Bramich, D. M., Brillant, S., Burgadorf, M., Caldwell, J. A. R., Calitz, H., Cassan, A., Cook, K. H., Corrales, E., Coutures, Ch., Desort, N., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fraser, S. N., Greenhill, J., Hill, K., Hoffman, M., Horne, K., Jorgensen, U. G., Kane, S. R., Kubas, D., Marquette, J. B., Martin, R., Meintjes, P., Menzies, J., Mottram, C., Naylor, T., Pollard, K. R., Sahu, K. C., Snodgrass, C., Steele, I., Vinter, C., Wambsganss, J., Williams, A., and Woller, K.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We present the analysis result of a gravitational binary-lensing event OGLE-2005-BLG-018. The light curve of the event is characterized by 2 adjacent strong features and a single weak feature separated from the strong features. The light curve exhibits noticeable deviations from the best-fit model based on standard binary parameters. To explain the deviation, we test models including various higher-order effects of the motions of the observer, source, and lens. From this, we find that it is necessary to account for the orbital motion of the lens in describing the light curve. From modeling of the light curve considering the parallax effect and Keplerian orbital motion, we are able to measure not only the physical parameters but also a complete orbital solution of the lens system. It is found that the event was produced by a binary lens located in the Galactic bulge with a distance $6.7\pm 0.3$ kpc from the Earth. The individual lens components with masses $0.9\pm 0.3\ M_\odot$ and $0.5\pm 0.1\ M_\odot$ are separated with a semi-major axis of $a=2.5 \pm 1.0$ AU and orbiting each other with a period $P=3.1 \pm 1.3$ yr. The event demonstrates that it is possible to extract detailed information about binary lens systems from well-resolved lensing light curves., Comment: 19 pages, 6 figures

Published
2011
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46. 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
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
2010
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47. 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, To., 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., 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, Ch., Dieters, S., Fouqué, P., Greenhill, J., Menzies, J., Allan, A., Bramich, D. M., Browne, P., Horne, K., Kains, N., Snodgrass, C., Steele, I., Tsapras, Y., Bozza, V., Burgdorf, M. J., Novati, S. Calchi, 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, G., Skottfelt, J., Surdej, J., Southworth, J., Wambsganss, J., and Zimmer, F.

Subjects
Astrophysics - Solar and Stellar Astrophysics
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., Comment: 18 pages, 5 figures, 1 table

Published
2010
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48. OGLE-2005-BLG-153: Microlensing Discovery and Characterization of A Very Low Mass Binary

Author

Hwang, K. -H., Udalski, A., Han, C., Ryu, Y. -H., Bond, I. A., Beaulieu, J. -P., Dominik, M., Horne, K., Gould, A., Gaudi, B. S., Kubiak, M., Szymanski, M. K., Pietrzynski, G., Soszynski, I., Szewczyk, O., Ulaczyk, K., Wyrzykowski, L., Abe, F., Botzler, C. S., Hearnshaw, J. B., Itow, Y., Kamiya, K., Kilmartin, P. M., Masuda, K., Matsubara, Y., Motomura, M., Muraki, Y., Nakamura, S., Ohnishi, K., Okada, C., Rattenbury, N., Saito, To., Sako, T., Sasaki, M., Sullivan, D. J., Sumi, T., Tristram, P. J., Wood, J. N., Yock, P. C. M., Yoshioka, T., Albrow, M., Bennett, D. P., Bramich, D. M., Brillant, S., Caldwell, J. A. R., Calitz, J. J., Cassan, A., Cook, K. H., Corrales, E., Coutures, C., Desort, M., Dieters, S., Dominis, D., Donatowicz, J., Fouque, P., Greenhill, J., Harpsoe, K., Hill, K., Hoffman, M., Jorgensen, U. G., Kane, S., Kubas, D., Martin, R., Marquette, J. -B., Meintjes, P., Menzies, J., Pollard, K., Sahu, K., Steele, I., Vinter, C., Wambsganss, J., Williams, A., Woller, K., Burgdorf, M., Snodgrass, C., Bode, M., Depoy, D. L., Lee, C. -U., Park, B. -G., and Pogge, R. W.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The mass function and statistics of binaries provide important diagnostics of the star formation process. Despite this importance, the mass function at low masses remains poorly known due to observational difficulties caused by the faintness of the objects. Here we report the microlensing discovery and characterization of a binary lens composed of very low-mass stars just above the hydrogen-burning limit. From the combined measurements of the Einstein radius and microlens parallax, we measure the masses of the binary components of $0.10\pm 0.01\ M_\odot$ and $0.09\pm 0.01\ M_\odot$. This discovery demonstrates that microlensing will provide a method to measure the mass function of all Galactic populations of very low mass binaries that is independent of the biases caused by the luminosity of the population., Comment: 6 pages, 3 figures, 1 table

Published
2010
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49. 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., Fouqué, 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., and Santallo, R.

Subjects
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., Comment: 39 pages, 10 figures, accepted for publication in ApJ

Published
2009
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50. Interpretation of Strong Short-Term Central Perturbations in the Light Curves of Moderate-Magnification Microlensing Events

Author

Han, C., Hwang, K. -H., Kim, D., Udalski, A., Abe, F., Monard, L. A. B., McCormick, J., Szymanski, M. K., Kubiak, M., Pietrzynski, G., Soszynski, I., Szewczyk, O., Wyrzykowski, L., Ulaczyk, K., 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., Miyake, N., Muraki, Y., Nagaya, M., Ohnishi, K., Tokumura, T., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Skuljan, L., Sullivan, D. S., Sumi, T., Sweatman, W. L., Tristram, P. J., Yock, P. C. M., Allen, W., Christie, G. W., DePoy, D. L., Dong, S., Gaudi, B. S., Gould, A., Lee, C. -U., Natusch, T., Park, B. -G., Pogge, R. W., Albrow, M. D., Allan, A., Batista, V., Beaulieu, J. P., Bennett, D. P., Brillant, S., Bode, M., Bramich, D. M., Burgdorf, M., Caldwell, J. A. R., Calitz, H., Cassan, A., Corrales, E., Dieters, S., Prester, D. D., Dominik, M., Donatowicz, J., Fouque, P., Greenhill, J., Hill, K., Hoffman, M., Horne, K., Jorgensen, U. G., Kains, N., Kubas, D., 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., and Zub, M.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

To improve the planet detection efficiency, current planetary microlensing experiments are focused on high-magnification events searching for planetary signals near the peak of lensing light curves. However, it is known that central perturbations can also be produced by binary companions and thus it is important to distinguish planetary signals from those induced by binary companions. In this paper, we analyze the light curves of microlensing events OGLE-2007-BLG-137/MOA-2007-BLG-091, OGLE-2007-BLG-355/MOA-2007-BLG-278, and MOA-2007-BLG-199/OGLE-2007-BLG-419, for all of which exhibit short-term perturbations near the peaks of the light curves. From detailed modeling of the light curves, we find that the perturbations of the events are caused by binary companions rather than planets. From close examination of the light curves combined with the underlying physical geometry of the lens system obtained from modeling, we find that the short time-scale caustic-crossing feature occurring at a low or a moderate base magnification with an additional secondary perturbation is a typical feature of binary-lens events and thus can be used for the discrimination between the binary and planetary interpretations., Comment: 17 pages, 4 figures, 1 table

Published
2009
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