Abstract
Despite the 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 two 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 and 0.39 M for MOA-2011-BLG-090 and 0.57 M and 0.17 M 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.
Original language | English |
---|---|
Article number | 91 |
Journal | Astrophysical Journal |
Volume | 755 |
Issue number | 2 |
DOIs | |
Publication status | Published - 20 Aug 2012 |
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Keywords
- binaries: general
- gravitational lensing: micro
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Characterizing low-mass binaries from observation of long-timescale caustic-crossing gravitational microlensing events. / Shin, I. G.; Han, C.; Choi, J. Y.; 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; 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.; Al-Subai, Khalid; Browne, P.; Burgdorf, M. J.; Novati, S. Calchi; Dodds, P.; Dreizler, S.; Fang, X. S.; Grundahl, F.; Gu, C. H.; Hardis, S.; Harpsoe, K.; Hinse, T. C.; Hornstrup, A.; Hundertmark, M.; Jessen-Hansen, J.; Jorgensen, 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.; Zub, And M.
In: Astrophysical Journal, Vol. 755, No. 2, 91, 20.08.2012.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Characterizing low-mass binaries from observation of long-timescale caustic-crossing gravitational microlensing events
AU - Shin, I. G.
AU - Han, C.
AU - Choi, J. Y.
AU - Udalski, A.
AU - Sumi, T.
AU - Gould, A.
AU - Bozza, V.
AU - Dominik, M.
AU - Fouqué, P.
AU - Horne, K.
AU - Szymański, M. K.
AU - Kubiak, M.
AU - Soszyński, I.
AU - Pietrzyński, G.
AU - Poleski, R.
AU - Ulaczyk, K.
AU - Pietrukowicz, P.
AU - Kozłowski, S.
AU - Skowron, J.
AU - Wyrzykowski,
AU - Abe, F.
AU - Bennett, D. P.
AU - Bond, I. A.
AU - Botzler, C. S.
AU - Chote, P.
AU - Freeman, M.
AU - Fukui, A.
AU - Furusawa, K.
AU - Itow, Y.
AU - Kobara, S.
AU - Ling, C. H.
AU - Masuda, K.
AU - Matsubara, Y.
AU - Miyake, N.
AU - Muraki, Y.
AU - Ohmori, K.
AU - Ohnishi, K.
AU - Rattenbury, N. J.
AU - Saito, To
AU - Sullivan, D. J.
AU - Suzuki, D.
AU - Suzuki, K.
AU - Sweatman, W. L.
AU - Takino, S.
AU - Tristram, P. J.
AU - Wada, K.
AU - Yock, P. C M
AU - Bramich, D. M.
AU - Snodgrass, C.
AU - Steele, I. A.
AU - Street, R. A.
AU - Tsapras, Y.
AU - Al-Subai, Khalid
AU - Browne, P.
AU - Burgdorf, M. J.
AU - Novati, S. Calchi
AU - Dodds, P.
AU - Dreizler, S.
AU - Fang, X. S.
AU - Grundahl, F.
AU - Gu, C. H.
AU - Hardis, S.
AU - Harpsoe, K.
AU - Hinse, T. C.
AU - Hornstrup, A.
AU - Hundertmark, M.
AU - Jessen-Hansen, J.
AU - Jorgensen, U. G.
AU - Kains, N.
AU - Kerins, E.
AU - Liebig, C.
AU - Lund, M.
AU - Lunkkvist, M.
AU - Mancini, L.
AU - Mathiasen, M.
AU - Penny, M. T.
AU - Rahvar, S.
AU - Ricci, D.
AU - Scarpetta, G.
AU - Skottfelt, J.
AU - Southworth, J.
AU - Surdej, J.
AU - Tregloan-Reed, J.
AU - Wambsganss, J.
AU - Wertz, O.
AU - Almeida, L. A.
AU - Batista, V.
AU - Christie, G.
AU - Depoy, D. L.
AU - Dong, Subo
AU - Gaudi, B. S.
AU - Henderson, C.
AU - Jablonski, F.
AU - Lee, C. U.
AU - McCormick, J.
AU - McGregor, D.
AU - Moorhouse, D.
AU - Natusch, T.
AU - Ngan, H.
AU - Park, S. Y.
AU - Pogge, R. W.
AU - Tan, T. G.
AU - Thornley, G.
AU - Yee, J. C.
AU - Albrow, M. D.
AU - Bachelet, E.
AU - Beaulieu, J. P.
AU - Brillant, S.
AU - Cassan, A.
AU - Cole, A. A.
AU - Corrales, E.
AU - Coutures, C.
AU - Dieters, S.
AU - Prester, D. Dominis
AU - Donatowicz, J.
AU - Greenhill, J.
AU - Kubas, D.
AU - Marquette, J. B.
AU - Menzies, J. W.
AU - Sahu, K. C.
AU - Zub, And M.
PY - 2012/8/20
Y1 - 2012/8/20
N2 - Despite the 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 two 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 and 0.39 M for MOA-2011-BLG-090 and 0.57 M and 0.17 M 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.
AB - Despite the 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 two 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 and 0.39 M for MOA-2011-BLG-090 and 0.57 M and 0.17 M 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.
KW - binaries: general
KW - gravitational lensing: micro
UR - http://www.scopus.com/inward/record.url?scp=84864691489&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84864691489&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/755/2/91
DO - 10.1088/0004-637X/755/2/91
M3 - Article
AN - SCOPUS:84864691489
VL - 755
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 91
ER -