A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L

E. Bachelet; P. Fouque; C. Han; A. Gould; M. D. Albrow; J. -P. Beaulieu; E. Bertin; I. A. Bond; G. W. Christie; D. Heyrovsky; K. Horne; U. G. Jorgensen; D. Maoz; M. Mathiasen; N. Matsunaga; J. McCormick; J. Menzies; D. Nataf; T. Natusch; N. Oi; N. Renon; Y. Tsapras; A. Udalski; J. C. Yee; V. Batista; D. P. Bennett; S. Brillant; J. A. R. Caldwell; A. Cassan; A. Cole; K. H. Cook; C. Coutures; S. Dieters; M. Dominik; D. Dominis Prester; J. Donatowicz; J. Greenhill; N. Kains; S. R. Kane; J. -B. Marquette; R. Martin; K. R. Pollard; K. C. Sahu; R. A. Street; J. Wambsganss; A. Williams; M. Zub; M. Bos; Subo Dong; J. Drummond; B. S. Gaudi; D. Graff; J. Janczak; S. Kaspi; S. Kozlowski; C. -U. Lee; L. A. G. Monard; J. A. Munoz; B. -G. Park; R. W. Pogge; D. Polishook; A. Shporer; F. Abe; C. S. Botzler; A. Fukui; K. Furusawa; J. B. Hearnshaw; Y. Itow; A. V. Korpela; C. H. Ling; K. Masuda; Y. Matsubara; N. Miyake; Y. Muraki; K. Ohnishi; N. J. Rattenbury; To. Saito; D. Sullivan; T. Sumi; D. Suzuki; W. L. Sweatman; P. J. Tristram; K. Wada; A. Allan; M. F. Bode; D. M. Bramich; N. Clay; S. N. Fraser; E. Hawkins; E. Kerins; T. A. Lister; C. J. Mottram; E. S. Saunders; C. Snodgrass; I. A. Steele; P. J. Wheatley; V. Bozza; P. Browne; M. J. Burgdorf; S. Calchi Novati; S. Dreizler; F. Finet; M. Glitrup; F. Grundahl; K. Harpsoe; F. V. Hessman; T. C. Hinse; M. Hundertmark; C. Liebig; G. Maier; L. Mancini; S. Rahvar; D. Ricci; G. Scarpetta; J. Skottfelt; J. Southworth; J. Surdej; F. Zimmer

doi:10.1051/0004-6361/201219765

A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L

E. Bachelet, P. Fouque, C. Han, A. Gould, M. D. Albrow, J. -P. Beaulieu, E. Bertin, I. A. Bond, G. W. Christie, D. Heyrovsky, K. Horne, U. G. Jorgensen, D. Maoz, M. Mathiasen, N. Matsunaga, J. McCormick, J. Menzies, D. Nataf, T. Natusch, N. OiN. Renon, Y. Tsapras, A. Udalski, J. C. Yee, V. Batista, D. P. Bennett, S. Brillant, J. A. R. Caldwell, A. Cassan, A. Cole, K. H. Cook, C. Coutures, S. Dieters, M. Dominik, D. Dominis Prester, J. Donatowicz, J. Greenhill, N. Kains, S. R. Kane, J. -B. Marquette, R. Martin, K. R. Pollard, K. C. Sahu, R. A. Street, J. Wambsganss, A. Williams, M. Zub, M. Bos, Subo Dong, J. Drummond, B. S. Gaudi, D. Graff, J. Janczak, S. Kaspi, S. Kozlowski, C. -U. Lee, L. A. G. Monard, J. A. Munoz, B. -G. Park, R. W. Pogge, D. Polishook, A. Shporer, F. Abe, C. S. Botzler, A. Fukui, K. Furusawa, J. B. Hearnshaw, Y. Itow, A. V. Korpela, C. H. Ling, K. Masuda, Y. Matsubara, N. Miyake, Y. Muraki, K. Ohnishi, N. J. Rattenbury, To. Saito, D. Sullivan, T. Sumi, D. Suzuki, W. L. Sweatman, P. J. Tristram, K. Wada, A. Allan, M. F. Bode, D. M. Bramich, N. Clay, S. N. Fraser, E. Hawkins, E. Kerins, T. A. Lister, C. J. Mottram, E. S. Saunders, C. Snodgrass, I. A. Steele, P. J. Wheatley, V. Bozza, P. Browne, M. J. Burgdorf, S. Calchi Novati, S. Dreizler, F. Finet, M. Glitrup, F. Grundahl, K. Harpsoe, F. V. Hessman, T. C. Hinse, M. Hundertmark, C. Liebig, G. Maier, L. Mancini, S. Rahvar, D. Ricci, G. Scarpetta, J. Skottfelt, J. Southworth, J. Surdej, F. Zimmer

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

17 Citations (Scopus)

Abstract

Context. Caustic crossing is the clearest signature of binary lenses in microlensing. In the present context, this signature is diluted by the large source star but a detailed analysis has allowed the companion signal to be extracted.

Aims. MOA 2009-BLG-411 was detected on August 5, 2009 by the MOA-Collaboration. Alerted as a high-magnification event, it was sensitive to planets. Suspected anomalies in the light curve were not confirmed by a real-time model, but further analysis revealed small deviations from a single lens extended source fit.

Methods. Thanks to observations by all the collaborations, this event was well monitored. We first decided to characterize the source star properties by using a more refined method than the classical one: we measure the interstellar absorption along the line of sight in five different passbands (VIJHK). Secondly, we model the lightcurve by using the standard technique: make (s, q, alpha) grids to look for local minima and refine the results by using a downhill method (Markov chain Monte Carlo). Finally, we use a Galactic model to estimate the physical properties of the lens components.

Results. We find that the source star is a giant G star with radius 9 R-circle dot. The grid search gives two local minima, which correspond to the theoretical degeneracy s = s(-1). We find that the lens is composed of a brown dwarf secondary of mass M-S = 0.05 M-circle dot orbiting a primary M-star of mass M-P = 0.18 M-circle dot. We also reveal a new mass-ratio degeneracy for the central caustics of close binaries.

Conclusions. As far as we are aware, this is the first detection using the microlensing technique of a binary system in our Galaxy composed of an M-star and a brown dwarf.

Original language	English
Article number	A55
Number of pages	12
Journal	Astronomy & Astrophysics
Volume	547
DOIs	https://doi.org/10.1051/0004-6361/201219765
Publication status	Published - Nov 2012

Keywords

binaries: general
gravitational lensing: micro
stars: individual: MOA 2009-BLG-411L
MAGNIFICATION MICROLENSING EVENTS
SURFACE BRIGHTNESS RELATIONS
DIFFERENCE IMAGE-ANALYSIS
CLUMP ABSOLUTE MAGNITUDE
GALACTIC BULGE FIELDS
INTERSTELLAR EXTINCTION
BINARY INTERPRETATIONS
CENTRAL PERTURBATIONS
PLANETARY SYSTEMS
MASS PLANET

Access to Document

10.1051/0004-6361/201219765

Astrophysics at St Andrews:2012 - 2014: Astrophysics at St Andrews: 2012 - 2014
Horne, K. D. (PI)
Science & Technology Facilities Council
1/10/11 → 31/03/12
Project: Standard

Cite this

Bachelet, E., Fouque, P., Han, C., Gould, A., Albrow, M. D., Beaulieu, J. .-P., Bertin, E., Bond, I. A., Christie, G. W., Heyrovsky, D., Horne, K., Jorgensen, U. G., Maoz, D., Mathiasen, M., Matsunaga, N., McCormick, J., Menzies, J., Nataf, D., Natusch, T., ... Zimmer, F. (2012). A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L. Astronomy & Astrophysics, 547, Article A55. https://doi.org/10.1051/0004-6361/201219765

@article{c1730bd2800d466e90cc0890840d8437,

title = "A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L",

abstract = "Context. Caustic crossing is the clearest signature of binary lenses in microlensing. In the present context, this signature is diluted by the large source star but a detailed analysis has allowed the companion signal to be extracted.Aims. MOA 2009-BLG-411 was detected on August 5, 2009 by the MOA-Collaboration. Alerted as a high-magnification event, it was sensitive to planets. Suspected anomalies in the light curve were not confirmed by a real-time model, but further analysis revealed small deviations from a single lens extended source fit.Methods. Thanks to observations by all the collaborations, this event was well monitored. We first decided to characterize the source star properties by using a more refined method than the classical one: we measure the interstellar absorption along the line of sight in five different passbands (VIJHK). Secondly, we model the lightcurve by using the standard technique: make (s, q, alpha) grids to look for local minima and refine the results by using a downhill method (Markov chain Monte Carlo). Finally, we use a Galactic model to estimate the physical properties of the lens components.Results. We find that the source star is a giant G star with radius 9 R-circle dot. The grid search gives two local minima, which correspond to the theoretical degeneracy s = s(-1). We find that the lens is composed of a brown dwarf secondary of mass M-S = 0.05 M-circle dot orbiting a primary M-star of mass M-P = 0.18 M-circle dot. We also reveal a new mass-ratio degeneracy for the central caustics of close binaries.Conclusions. As far as we are aware, this is the first detection using the microlensing technique of a binary system in our Galaxy composed of an M-star and a brown dwarf.",

keywords = "binaries: general, gravitational lensing: micro, stars: individual: MOA 2009-BLG-411L, MAGNIFICATION MICROLENSING EVENTS, SURFACE BRIGHTNESS RELATIONS, DIFFERENCE IMAGE-ANALYSIS, CLUMP ABSOLUTE MAGNITUDE, GALACTIC BULGE FIELDS, INTERSTELLAR EXTINCTION, BINARY INTERPRETATIONS, CENTRAL PERTURBATIONS, PLANETARY SYSTEMS, MASS PLANET",

author = "E. Bachelet and P. Fouque and C. Han and A. Gould and Albrow, {M. D.} and Beaulieu, {J. -P.} and E. Bertin and Bond, {I. A.} and Christie, {G. W.} and D. Heyrovsky and K. Horne and Jorgensen, {U. G.} and D. Maoz and M. Mathiasen and N. Matsunaga and J. McCormick and J. Menzies and D. Nataf and T. Natusch and N. Oi and N. Renon and Y. Tsapras and A. Udalski and Yee, {J. C.} and V. Batista and Bennett, {D. P.} and S. Brillant and Caldwell, {J. A. R.} and A. Cassan and A. Cole and Cook, {K. H.} and C. Coutures and S. Dieters and M. Dominik and Prester, {D. Dominis} and J. Donatowicz and J. Greenhill and N. Kains and Kane, {S. R.} and Marquette, {J. -B.} and R. Martin and Pollard, {K. R.} and Sahu, {K. C.} and Street, {R. A.} and J. Wambsganss and A. Williams and M. Zub and M. Bos and Subo Dong and J. Drummond and Gaudi, {B. S.} and D. Graff and J. Janczak and S. Kaspi and S. Kozlowski and Lee, {C. -U.} and Monard, {L. A. G.} and Munoz, {J. A.} and Park, {B. -G.} and Pogge, {R. W.} and D. Polishook and A. Shporer and F. Abe and Botzler, {C. S.} and A. Fukui and K. Furusawa and Hearnshaw, {J. B.} and Y. Itow and Korpela, {A. V.} and Ling, {C. H.} and K. Masuda and Y. Matsubara and N. Miyake and Y. Muraki and K. Ohnishi and Rattenbury, {N. J.} and To. Saito and D. Sullivan and T. Sumi and D. Suzuki and Sweatman, {W. L.} and Tristram, {P. J.} and K. Wada and A. Allan and Bode, {M. F.} and Bramich, {D. M.} and N. Clay and Fraser, {S. N.} and E. Hawkins and E. Kerins and Lister, {T. A.} and Mottram, {C. J.} and Saunders, {E. S.} and C. Snodgrass and Steele, {I. A.} and Wheatley, {P. J.} and V. Bozza and P. Browne and Burgdorf, {M. J.} and {Calchi Novati}, S. and S. Dreizler and F. Finet and M. Glitrup and F. Grundahl and K. Harpsoe and Hessman, {F. V.} and Hinse, {T. C.} and M. Hundertmark and C. Liebig and G. Maier and L. Mancini and S. Rahvar and D. Ricci and G. Scarpetta and J. Skottfelt and J. Southworth and J. Surdej and F. Zimmer",

year = "2012",

month = nov,

doi = "10.1051/0004-6361/201219765",

language = "English",

volume = "547",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP SCIENCES S A",

}

Bachelet, E, Fouque, P, Han, C, Gould, A, Albrow, MD, Beaulieu, J-P, Bertin, E, Bond, IA, Christie, GW, Heyrovsky, D, Horne, K, Jorgensen, UG, Maoz, D, Mathiasen, M, Matsunaga, N, McCormick, J, Menzies, J, Nataf, D, Natusch, T, Oi, N, Renon, N, Tsapras, Y, Udalski, A, Yee, JC, Batista, V, Bennett, DP, Brillant, S, Caldwell, JAR, Cassan, A, Cole, A, Cook, KH, Coutures, C, Dieters, S, Dominik, M, Prester, DD, Donatowicz, J, Greenhill, J, Kains, N, Kane, SR, Marquette, J-B, Martin, R, Pollard, KR, Sahu, KC, Street, RA, Wambsganss, J, Williams, A, Zub, M, Bos, M, Dong, S, Drummond, J, Gaudi, BS, Graff, D, Janczak, J, Kaspi, S, Kozlowski, S, Lee, C-U, Monard, LAG, Munoz, JA, Park, B-G, Pogge, RW, Polishook, D, Shporer, A, Abe, F, Botzler, CS, Fukui, A, Furusawa, K, Hearnshaw, JB, Itow, Y, Korpela, AV, Ling, CH, Masuda, K, Matsubara, Y, Miyake, N, Muraki, Y, Ohnishi, K, Rattenbury, NJ, Saito, T, Sullivan, D, Sumi, T, Suzuki, D, Sweatman, WL, Tristram, PJ, Wada, K, Allan, A, Bode, MF, Bramich, DM, Clay, N, Fraser, SN, Hawkins, E, Kerins, E, Lister, TA, Mottram, CJ, Saunders, ES, Snodgrass, C, Steele, IA, Wheatley, PJ, Bozza, V, Browne, P, Burgdorf, MJ, Calchi Novati, S, Dreizler, S, Finet, F, Glitrup, M, Grundahl, F, Harpsoe, K, Hessman, FV, Hinse, TC, Hundertmark, M, Liebig, C, Maier, G, Mancini, L, Rahvar, S, Ricci, D, Scarpetta, G, Skottfelt, J, Southworth, J, Surdej, J & Zimmer, F 2012, 'A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L', Astronomy & Astrophysics, vol. 547, A55. https://doi.org/10.1051/0004-6361/201219765

TY - JOUR

T1 - A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L

AU - Bachelet, E.

AU - Fouque, P.

AU - Han, C.

AU - Gould, A.

AU - Albrow, M. D.

AU - Beaulieu, J. -P.

AU - Bertin, E.

AU - Bond, I. A.

AU - Christie, G. W.

AU - Heyrovsky, D.

AU - Horne, K.

AU - Jorgensen, U. G.

AU - Maoz, D.

AU - Mathiasen, M.

AU - Matsunaga, N.

AU - McCormick, J.

AU - Menzies, J.

AU - Nataf, D.

AU - Natusch, T.

AU - Oi, N.

AU - Renon, N.

AU - Tsapras, Y.

AU - Udalski, A.

AU - Yee, J. C.

AU - Batista, V.

AU - Bennett, D. P.

AU - Brillant, S.

AU - Caldwell, J. A. R.

AU - Cassan, A.

AU - Cole, A.

AU - Cook, K. H.

AU - Coutures, C.

AU - Dieters, S.

AU - Dominik, M.

AU - Prester, D. Dominis

AU - Donatowicz, J.

AU - Greenhill, J.

AU - Kains, N.

AU - Kane, S. R.

AU - Marquette, J. -B.

AU - Martin, R.

AU - Pollard, K. R.

AU - Sahu, K. C.

AU - Street, R. A.

AU - Wambsganss, J.

AU - Williams, A.

AU - Zub, M.

AU - Bos, M.

AU - Dong, Subo

AU - Drummond, J.

AU - Gaudi, B. S.

AU - Graff, D.

AU - Janczak, J.

AU - Kaspi, S.

AU - Kozlowski, S.

AU - Lee, C. -U.

AU - Monard, L. A. G.

AU - Munoz, J. A.

AU - Park, B. -G.

AU - Pogge, R. W.

AU - Polishook, D.

AU - Shporer, A.

AU - Abe, F.

AU - Botzler, C. S.

AU - Fukui, A.

AU - Furusawa, K.

AU - Hearnshaw, J. B.

AU - Itow, Y.

AU - Korpela, A. V.

AU - Ling, C. H.

AU - Masuda, K.

AU - Matsubara, Y.

AU - Miyake, N.

AU - Muraki, Y.

AU - Ohnishi, K.

AU - Rattenbury, N. J.

AU - Saito, To.

AU - Sullivan, D.

AU - Sumi, T.

AU - Suzuki, D.

AU - Sweatman, W. L.

AU - Tristram, P. J.

AU - Wada, K.

AU - Allan, A.

AU - Bode, M. F.

AU - Bramich, D. M.

AU - Clay, N.

AU - Fraser, S. N.

AU - Hawkins, E.

AU - Kerins, E.

AU - Lister, T. A.

AU - Mottram, C. J.

AU - Saunders, E. S.

AU - Snodgrass, C.

AU - Steele, I. A.

AU - Wheatley, P. J.

AU - Bozza, V.

AU - Browne, P.

AU - Burgdorf, M. J.

AU - Calchi Novati, S.

AU - Dreizler, S.

AU - Finet, F.

AU - Glitrup, M.

AU - Grundahl, F.

AU - Harpsoe, K.

AU - Hessman, F. V.

AU - Hinse, T. C.

AU - Hundertmark, M.

AU - Liebig, C.

AU - Maier, G.

AU - Mancini, L.

AU - Rahvar, S.

AU - Ricci, D.

AU - Scarpetta, G.

AU - Skottfelt, J.

AU - Southworth, J.

AU - Surdej, J.

AU - Zimmer, F.

PY - 2012/11

Y1 - 2012/11

N2 - Context. Caustic crossing is the clearest signature of binary lenses in microlensing. In the present context, this signature is diluted by the large source star but a detailed analysis has allowed the companion signal to be extracted.Aims. MOA 2009-BLG-411 was detected on August 5, 2009 by the MOA-Collaboration. Alerted as a high-magnification event, it was sensitive to planets. Suspected anomalies in the light curve were not confirmed by a real-time model, but further analysis revealed small deviations from a single lens extended source fit.Methods. Thanks to observations by all the collaborations, this event was well monitored. We first decided to characterize the source star properties by using a more refined method than the classical one: we measure the interstellar absorption along the line of sight in five different passbands (VIJHK). Secondly, we model the lightcurve by using the standard technique: make (s, q, alpha) grids to look for local minima and refine the results by using a downhill method (Markov chain Monte Carlo). Finally, we use a Galactic model to estimate the physical properties of the lens components.Results. We find that the source star is a giant G star with radius 9 R-circle dot. The grid search gives two local minima, which correspond to the theoretical degeneracy s = s(-1). We find that the lens is composed of a brown dwarf secondary of mass M-S = 0.05 M-circle dot orbiting a primary M-star of mass M-P = 0.18 M-circle dot. We also reveal a new mass-ratio degeneracy for the central caustics of close binaries.Conclusions. As far as we are aware, this is the first detection using the microlensing technique of a binary system in our Galaxy composed of an M-star and a brown dwarf.

AB - Context. Caustic crossing is the clearest signature of binary lenses in microlensing. In the present context, this signature is diluted by the large source star but a detailed analysis has allowed the companion signal to be extracted.Aims. MOA 2009-BLG-411 was detected on August 5, 2009 by the MOA-Collaboration. Alerted as a high-magnification event, it was sensitive to planets. Suspected anomalies in the light curve were not confirmed by a real-time model, but further analysis revealed small deviations from a single lens extended source fit.Methods. Thanks to observations by all the collaborations, this event was well monitored. We first decided to characterize the source star properties by using a more refined method than the classical one: we measure the interstellar absorption along the line of sight in five different passbands (VIJHK). Secondly, we model the lightcurve by using the standard technique: make (s, q, alpha) grids to look for local minima and refine the results by using a downhill method (Markov chain Monte Carlo). Finally, we use a Galactic model to estimate the physical properties of the lens components.Results. We find that the source star is a giant G star with radius 9 R-circle dot. The grid search gives two local minima, which correspond to the theoretical degeneracy s = s(-1). We find that the lens is composed of a brown dwarf secondary of mass M-S = 0.05 M-circle dot orbiting a primary M-star of mass M-P = 0.18 M-circle dot. We also reveal a new mass-ratio degeneracy for the central caustics of close binaries.Conclusions. As far as we are aware, this is the first detection using the microlensing technique of a binary system in our Galaxy composed of an M-star and a brown dwarf.

KW - binaries: general

KW - gravitational lensing: micro

KW - stars: individual: MOA 2009-BLG-411L

KW - MAGNIFICATION MICROLENSING EVENTS

KW - SURFACE BRIGHTNESS RELATIONS

KW - DIFFERENCE IMAGE-ANALYSIS

KW - CLUMP ABSOLUTE MAGNITUDE

KW - GALACTIC BULGE FIELDS

KW - INTERSTELLAR EXTINCTION

KW - BINARY INTERPRETATIONS

KW - CENTRAL PERTURBATIONS

KW - PLANETARY SYSTEMS

KW - MASS PLANET

U2 - 10.1051/0004-6361/201219765

DO - 10.1051/0004-6361/201219765

M3 - Article

SN - 0004-6361

VL - 547

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

M1 - A55

ER -

A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L

Abstract

Keywords

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