http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bozza, V.,Dominik, M.,Rattenbury, N. J.,Jørgensen, U. G.,Tsapras, Y.,Bramich, D. M.,Udalski, A.,Bond, I. A.,Liebig, C.,Cassan, A.,Fouqué,, P.,Fukui, A.,Hundertmark, M.,Shin, I.‐,G.,Lee, S. Blackwell Publishing Ltd 2012 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.424 No.2
<P><B>ABSTRACT</B></P><P>The microlensing event OGLE‐2008‐BLG‐510 is characterized by an evident asymmetric shape of the peak, promptly detected by the Automated Robotic Terrestrial Exoplanet Microlensing Search (ARTEMiS) system in real time. The skewness of the light curve appears to be compatible both with binary‐lens and binary‐source models, including the possibility that the lens system consists of an M dwarf orbited by a brown dwarf. The detection of this microlensing anomaly and our analysis demonstrate that: (1) automated real‐time detection of weak microlensing anomalies with immediate feedback is feasible, efficient and sensitive, (2) rather common weak features intrinsically come with ambiguities that are not easily resolved from photometric light curves, (3) a modelling approach that finds all features of parameter space rather than just the ‘favourite model’ is required and (4) the data quality is most crucial, where systematics can be confused with real features, in particular small higher order effects such as orbital motion signatures. It moreover becomes apparent that events with weak signatures are a silver mine for statistical studies, although not easy to exploit. Clues about the apparent paucity of both brown‐dwarf companions and binary‐source microlensing events might hide here.</P>
First Assessment of the Binary Lens OGLE-2015-BLG-0232
Bachelet, E.,Bozza, V.,Han, C.,Udalski, A.,Bond, I. A.,Beaulieu, J.-P.,Street, R. A.,Kim, H.-I,Bramich, D. M.,Cassan, A.,Dominik, M.,Jaimes, R. Figuera,Horne, K.,Hundertmark, M.,Mao, S.,Menzies, J.,Ra American Astronomical Society 2019 The Astrophysical journal Vol.870 No.1
Han, C.,Udalski, A.,Bozza, V.,Szymań,ski, M. K.,Soszyń,ski, I.,Skowron, J.,Mró,z, P.,Poleski, R.,Pietrukowicz, P.,Kozłowski, S.,Ulaczyk, K.,Wyrzykowski, Ł.,Novati, S. Calchi,D’Ago, G. American Astronomical Society 2017 The Astrophysical journal Vol.843 No.2
<P>Due to the nature of the gravitational field, microlensing, in principle, provides an important tool for detecting faint and even dark brown dwarfs. However, the number of identified brown dwarfs is limited due to the difficulty of the lens mass measurement that is needed to check the substellar nature of the lensing object. In this work, we report a microlensing brown dwarf discovered from an analysis of the gravitational binary-lens event OGLE-2014-BLG1112. We identify the brown dwarf nature of the lens companion by measuring the lens mass from the detections of both microlens-parallax and finite-source effects. We find that the companion has a mass of. ' ( 3.03 +/- 0.78) 10(-2) M-circle dot and it is orbiting a solar-type primary star with a mass of 1.07 +/- 0.28 M-circle dot. The estimated projected separation between the lens components is 9.63 +/- 1.33 au and the distance to the lens is 4.84 +/- 0.67 kpc. We discuss the usefulness of space-based microlensing observations for detecting brown dwarfs through the channel of binary-lens events.</P>
OGLE-2014-BLG-0289: Precise Characterization of a Quintuple-peak Gravitational Microlensing Event
Udalski, A.,Han, C.,Bozza, V.,Gould, A.,Bond, I. A.,Mró,z, P.,Skowron, J.,Wyrzykowski, Ł.,Szymań,ski, M. K.,Soszyń,ski, I.,Ulaczyk, K.,Poleski, R.,Pietrukowicz, P.,Kozłowski, S.,Abe, F American Astronomical Society 2018 The Astrophysical journal Vol.853 No.1
<P>We present the analysis of the binary-microlensing event OGLE-2014-BLG-0289. The event light curve exhibits five very unusual peaks, four of which were produced by caustic crossings and the other by a cusp approach. It is found that the quintuple-peak features of the light curve provide tight constraints on the source trajectory, enabling us to precisely and accurately measure the microlensing parallax pi(E). Furthermore, the three resolved caustics allow us to measure the angular Einstein radius theta(E). From the combination of pE and qE, the physical lens parameters are uniquely determined. It is found that the lens is a binary composed of two M dwarfs with masses M-1 = 0.52 +/- 0.04 M-circle dot and M-2 = 0.42 +/- 0.03 M-circle dot separated in projection by a(perpendicular to) = 6.4 +/- 0.5 au. The lens is located in the disk with a distance of D-L = 3.3 +/- 0.3 kpc. The reason for the absence of a lensing signal in the Spitzer data is that the time of observation corresponds to the flat region of the light curve.</P>
OGLE-2017-BLG-0482Lb: A Microlensing Super-Earth Orbiting a Low-mass Host Star
Han, C.,Hirao, Y.,Udalski, A.,Lee, C.-U.,Bozza, V.,Gould, A.,Abe, F.,Barry, R.,Bond, I. A.,Bennett, D. P.,Bhattacharya, A.,Donachie, M.,Evans, P.,Fukui, A.,Itow, Y.,Kawasaki, K.,Koshimoto, N.,Li, M. C American Astronomical Society 2018 The Astronomical journal Vol.155 No.5
OGLE-2017-BLG-0039: Microlensing Event with Light from a Lens Identified from Mass Measurement
Han, C.,Jung, Y. K.,Udalski, A.,Bond, I.,Bozza, V.,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.- American Astronomical Society 2018 The Astrophysical journal Vol.867 No.2
Mancini, L.,Giacobbe, P.,Littlefair, S. P.,Southworth, J.,Bozza, V.,Damasso, M.,Dominik, M.,Hundertmark, M.,Jørgensen, U. G.,Juncher, D.,Popovas, A.,Rabus, M.,Rahvar, S.,Schmidt, R. W.,Skottfelt, J.,S EDP Sciences 2015 Astronomy and astrophysics Vol.584 No.-
<P>Context. Photometric monitoring of the variability of brown dwarfs can provide useful information about the structure of clouds in their cold atmospheres.The brown-dwarf binary system Luhman16AB is an interesting target for such a study, because its components stand at the L/T transition and show high levels of variability. Luhman16AB is also the third closest system to the solar system, which allows precise astrometric investigations with ground-based facilities. Aims. The aim of the work is to estimate the rotation period and study the astrometric motion of both components. Methods. We have monitored Luhman16AB over a period of two years with the lucky-imaging camera mounted on the Danish 1.54m telescope at La Silla, through a special i + z long-pass filter, which allowed us to clearly resolve the two brown dwarfs into single objects. An intense monitoring of the target was also performed over 16 nights, in which we observed a peak-to-peak variability of 0.20±0.02mag and 0.34±0.02mag for Luhman16A and 16B, respectively. Results. We used the 16-night time-series data to estimate the rotation period of the two components. We found that Luhman16B rotates with a period of 5.1 ±0.1h, in very good agreement with previous measurements. For Luhman16A, we report that it rotates more slowly than its companion, and even though we were not able to get a robust determination, our data indicate a rotation period of roughly 8h. This implies that the rotation axes of the two components are well aligned and suggests a scenario in which the two objects underwent the same accretion process. The 2-year complete data set was used to study the astrometric motion of Luhman16AB. We predict a motion of the system that is not consistent with a previous estimate based on two months of monitoring, but cannot confirm or refute the presence of additional planetary-mass bodies in the system.</P>
<i>SPITZER</i>MICROLENS MEASUREMENT OF A MASSIVE REMNANT IN A WELL-SEPARATED BINARY
Shvartzvald, Y.,Udalski, A.,Gould, A.,Han, C.,Bozza, V.,Friedmann, M.,Hundertmark, M.,Beichman, C.,Bryden, G.,Novati, S. Calchi,Carey, S.,Fausnaugh, M.,Gaudi, B. S.,Henderson, C. B.,Kerr, T.,Pogge, R. IOP Publishing 2015 The Astrophysical journal Vol.814 No.2
<P>We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La, b, with the more massive component having M-1 > 1.35M(circle dot) (80% probability). A main-sequence star in this mass range is ruled out by limits on blue light, meaning that a primary in this mass range must be a neutron star (NS) or black hole (BH). The system has a projected separation r(perpendicular to) = 6.1 +/- 0.4 AU and lies in the Galactic bulge. These measurements are based on the 'microlens parallax' effect, i.e., comparing the microlensing light curve as seen from Spitzer, which lay at 1.25 AU projected from Earth, to the light curves from four ground-based surveys, three in the optical and one in the near-infrared. Future adaptive optics imaging of the companion by 30 m class telescopes will yield a much more accurate measurement of the primary mass. This discovery both opens the path and defines the challenges to detecting and characterizing BHs and NSs in wide binaries, with either dark or luminous companions. In particular, we discuss lessons that can be applied to future Spitzer and Kepler K2 microlensing parallax observations.</P>
Zhu (祝伟,), Wei,Udalski, A.,Gould, A.,Dominik, M.,Bozza, V.,Han, C.,Yee, J. C.,Novati, S. Calchi,Beichman, C. A.,Carey, S.,Poleski, R.,Skowron, J.,Kozłowski, S.,Mró,z, P.,Pietrukowicz, P.,P IOP Publishing 2015 The Astrophysical journal Vol.805 No.1
<P>We report the first mass and distance measurements of a caustic-crossing binary system OGLE-2014-BLG-1050 L using the space-based microlens parallax method. Spitzer captured the second caustic. crossing of the event, which occurred similar to 10 days before that seen from Earth. Due to the coincidence that the source-lens relative motion was almost parallel to the direction of the binary-lens axis, the fourfold degeneracy, which was known before only to occur in single-lens events, persists in this case, leading to either a lower-mass (0.2 and 0.07 M-circle dot) binary at similar to 1.1 kpc or a higher-mass (0.9 and 0.35 M-circle dot) binary at similar to 3.5 kpc. However, the latter solution is strongly preferred for reasons including blending and lensing probability. OGLE-2014-BLG-1050 L demonstrates the power of microlens parallax in probing stellar and substellar binaries.</P>