3 results for Abe, F.

  • Reanalyses of anomalous gravitational microlensing events in the OGLE-III early warning system database with combined data

    Jeong, J.; Park, H.; Han, C.; Gould, A.; Udalski, A.; Szymanski, M.K.; Pietrzynski, G.; Soszynski, I.; Poleski, R.; Ulaczyk, K.; Wyrzykowski, L.; Abe, F.; Bennett, D.P.; Bond, I.A.; Botzler, C.S.; Freeman, M.; Fukui, A.; Fukunaga, D.; Itow, Y.; Koshimoto, N.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Namba, S.; Ohnishi, K.; Rattenbury, N.J.; Saito, To.; Sullivan, D.J.; Sweatman, W.L.; Sumi, T.; Suzuki, D.; Tristram, P.J.; Tsurumi, N.; Wada, K.; Yamai, N.; Yock, P.C.M.; Yonehara, A.; Albrow, M.D.; Batista, V.; Beaulieu, J-P.; Caldwell, J.A.R.; Cassan, A.; Cole, A.; Coutures, C.; Dieters, S.; Dominik, M.; Dominis Prester, D.; Donatowicz, J.; Fouqué, P.; Greenhill, J.; Hoffman, M.; Huber, M.; Jørgensen, U.G.; Kane, S.R.; Kubas, D.; Martin, R.; Marquette, J.B.; Menzies, J.; Pitrou, C.; Pollard, K.; Sahu, K.C.; Vinter, C.; Wambsganss, J.; Williams, A.; Allen, W.; Bolt, G.; Choi, J.Y.; Christie, G.W.; DePoy, D.L.; Drummond, J.; Gaudi, B.S.; Hwang, K-H.; Jung, Y.K.; Lee, C-U.; Mallia, F.; Maoz, D.; Maury, A.; McCormick, J.; Monard, L.A.G.; Moorhouse, D.; Natusch, T.; Ofek, E.O.; Park, B-G.; Pogge, R.W.; Santallo, R.; Shin, I.G.; Thornley, G.; Yee, J.C.; Bramich, D.M.; Burgdorf, M.; Horne, K.; Hundertmark, M.; Kains, N.; Snodgrass, C.; Steele, I.; Street, R.; Tsapras, Y. (2015)

    Journal Articles
    University of Canterbury Library

    We reanalyze microlensing events in the published list of anomalous events that were observed from the Optical Gravitational Lensing Experiment (OGLE) lensing survey conducted during the 2004–2008 period. In order to check the existence of possible degenerate solutions and extract extra information, we conduct analyses based on combined data from other survey and follow-up observation and consider higher-order effects. Among the analyzed events, we present analyses of eight events for which either new solutions are identified or additional information is obtained. We find that the previous binary-source interpretations of five events are better interpreted by binary-lens models. These events include OGLE-2006-BLG-238, OGLE-2007-BLG-159, OGLE-2007-BLG- 491, OGLE-2008-BLG-143, and OGLE-2008-BLG-210. With additional data covering caustic crossings, we detect finite-source effects for six events including OGLE-2006-BLG-215, OGLE-2006-BLG-238, OGLE-2006- BLG-450, OGLE-2008-BLG-143, OGLE-2008-BLG-210, and OGLE-2008-BLG-513. Among them, we are able to measure the Einstein radii of three events for which multi-band data are available. These events are OGLE-2006- BLG-238, OGLE-2008-BLG-210, and OGLE-2008-BLG-513. For OGLE-2008-BLG-143, we detect higher-order effects induced by the changes of the observer’s position caused by the orbital motion of the Earth around the Sun. In addition, we present degenerate solutions resulting from the known close/wide or ecliptic degeneracy. Finally, we note that the masses of the binary companions of the lenses of OGLE-2006-BLG-450 and OGLE-2008-BLG- 210 are in the brown-dwarf regime.

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  • A Super-Jupiter Orbiting a Late-type Star: A Refined Analysis of Microlensing Event OGLE-2012-BLG-0406

    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.; Calchi Novati, S.; 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.; Kozlowski, S.; Wyrzykowski, L.; Szymanski, M.K.; Kubiak, M.; Pietrukowicz, P.; Pietrzynski, G.; Soszynski, 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.; Dominis Prester, D.; Donatowicz, J.; Fouqué, P.; Greenhill, J.; Kane, S.R.; Kubas, D.; Marquette, J-B.; Menzies, J.; Père, C.; Pollard, K.R.; Zub, M.; 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.; Yock, P.C.M.; Yonehara, A. (2014)

    Journal Articles
    University of Canterbury Library

    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 light curve, 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±0.43 MJ planet orbiting a 0.44±0.07M early M-type star. The distance to the lens is 4.97±0.29 kpc and the projected separation between the host star and its planet at the time of the event is 3.45±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.

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  • OGLE-2005-BLG-071Lb, the Most Massive M Dwarf Planetary Companion?

    Christie, G.W.; Gaudi, B.S.; Kubiak, M.; Szymanski, M.K.; Pietrzynski, G.; Soszynski, I.; Szewczyk, O.; Ulaczyk, K.; Wyrzykowski, L.; Fox, D.B.; Gal-Yam, A.; Han, C.; Lepine, S.; McCormick, J.; Ofek, E.; Park, B.G.; Pogge, R.W.; Abe, F.; Bennett, D.P.; Bond, I.A.; Britton, T.R.; Gilmore, A.C.; Hearnshaw, J.B.; Itow, Y.; Kamiya, K.; Kilmartin, P.M.; Korpela, A.; Masuda, K.; Matsubara, Y.; Motomura, M.; Muraki, Y.; Nakamura, S.; Ohnishi, K.; Okada, C.; Rattenbury, N.; Saito, T.; Sako, T.; Sasaki, M.; Sullivan, D.; Sumi, T.; Tristram, P.J.; Yanagisawa, T.; Yock, P.C.M.; Yoshoika, T.; Beaulieu, J.P.; Brillant, S.; Calitz, H.; Cassan, A.; Cook, K.H.; Coutures, C.; Dieters, S.; Prester, D.D.; Donatowicz, J.; Fouque, P.; Greenhill, J.; Hill, K.; Hoffman, M.; Horne, K.; Jaroszynski, M.; Dong, S.; Albrow, M.D.; Gould, A.; DePoy, D.L.; Udalski, A.; Anderson, J. (2009)

    Journal Articles
    University of Canterbury Library

    We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, the second planet discovered by microlensing and the first in a high-magnification event. These include photometric and astrometric measurements from Hubble Space Telescope, as well as constraints from higher order effects extracted from the ground-based light curve, such as microlens parallax, planetary orbital motion and finite-source effects. Our primary analysis leads to the conclusion that the host of Jovian planet OGLE-2005-BLG-071Lb is an M dwarf in the foreground disk with mass M= 0.46 +/- 0.04 Msun, distance D_l = 3.3 +/- 0.4 kpc, and thick-disk kinematics v_LSR ~ 103 km/s. From the best-fit model, the planet has mass M_p = 3.8 +/- 0.4 M_Jup, lies at a projected separation r_perp = 3.6 +/- 0.2 AU from its host and so has an equilibrium temperature of T ~ 55 K, i.e., similar to Neptune. A degenerate model less favored by \Delta\chi^2 = 2.1 (or 2.2, depending on the sign of the impact parameter) gives similar planetary mass M_p = 3.4 +/- 0.4 M_Jup with a smaller projected separation, r_\perp = 2.1 +/- 0.1 AU, and higher equilibrium temperature T ~ 71 K. These results from the primary analysis suggest that OGLE-2005-BLG-071Lb is likely to be the most massive planet yet discovered that is hosted by an M dwarf. However, the formation of such high-mass planetary companions in the outer regions of M-dwarf planetary systems is predicted to be unlikely within the core-accretion scenario. There are a number of caveats to this primary analysis, which assumes (based on real but limited evidence) that the unlensed light coincident with the source is actually due to the lens, that is, the planetary host. However, these caveats could mostly be resolved by a single astrometric measurement a few years after the event.

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