A brown dwarf orbiting an M-dwarf

MOA 2009-BLG-411L

E. Bachelet, P. Fouqué, C. Han, A. Gould, M. D. Albrow, J. P. Beaulieu, E. Bertin, I. A. Bond, G. W. Christie, D. Heyrovský, K. Horne, U. G. Jørgensen, D. Maoz, M. Mathiasen, N. Matsunaga, J. McCormick, J. Menzies, D. Nataf, T. Natusch, N. Oi & 98 others 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. Kozłowski, C. U. Lee, L. A G Monard, J. A. Muñoz, 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. Harpsøe, 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

Research output: Contribution to journalArticle

14 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,α) 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 ·. 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 MS = 0.05 M· orbiting a primary M-star of mass MP = 0.18 M·. 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 languageEnglish
Article numberA55
JournalAstronomy and Astrophysics
Volume547
DOIs
Publication statusPublished - 30 Oct 2012
Externally publishedYes

Fingerprint

lenses
M stars
stars
alkalies
grids
signatures
Markov chain
G stars
giant stars
Markov chains
planet
physical property
magnification
mass ratios
line of sight
light curve
anomaly
planets
physical properties
anomalies

Keywords

  • Binaries: general
  • Gravitational lensing: micro
  • Stars: individual: MOA 2009-BLG-411L

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Bachelet, E., Fouqué, P., Han, C., Gould, A., Albrow, M. D., Beaulieu, J. P., ... Zimmer, F. (2012). A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L. Astronomy and Astrophysics, 547, [A55]. https://doi.org/10.1051/0004-6361/201219765

A brown dwarf orbiting an M-dwarf : MOA 2009-BLG-411L. / Bachelet, E.; Fouqué, P.; Han, C.; Gould, A.; Albrow, M. D.; Beaulieu, J. P.; Bertin, E.; Bond, I. A.; Christie, G. W.; Heyrovský, D.; Horne, K.; Jørgensen, U. G.; Maoz, D.; Mathiasen, M.; Matsunaga, N.; McCormick, J.; Menzies, J.; Nataf, D.; Natusch, T.; Oi, N.; Renon, N.; Tsapras, Y.; Udalski, A.; Yee, J. C.; Batista, V.; Bennett, D. P.; Brillant, S.; Caldwell, J. A R; Cassan, A.; Cole, A.; Cook, K. H.; Coutures, C.; Dieters, S.; Dominik, M.; Dominis Prester, D.; Donatowicz, J.; Greenhill, J.; Kains, N.; Kane, S. R.; Marquette, J. B.; Martin, R.; Pollard, K. R.; Sahu, K. C.; Street, R. A.; Wambsganss, J.; Williams, A.; Zub, M.; Bos, M.; Dong, Subo; Drummond, J.; Gaudi, B. S.; Graff, D.; Janczak, J.; Kaspi, S.; Kozłowski, S.; Lee, C. U.; Monard, L. A G; Muñoz, J. A.; Park, B. G.; Pogge, R. W.; Polishook, D.; Shporer, A.; Abe, F.; Botzler, C. S.; Fukui, A.; Furusawa, K.; Hearnshaw, J. B.; Itow, Y.; Korpela, A. V.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Miyake, N.; Muraki, Y.; Ohnishi, K.; Rattenbury, N. J.; Saito, To; Sullivan, D.; Sumi, T.; Suzuki, D.; Sweatman, W. L.; Tristram, P. J.; Wada, K.; Allan, A.; Bode, M. F.; Bramich, D. M.; Clay, N.; Fraser, S. N.; Hawkins, E.; Kerins, E.; Lister, T. A.; Mottram, C. J.; Saunders, E. S.; Snodgrass, C.; Steele, I. A.; Wheatley, P. J.; Bozza, V.; Browne, P.; Burgdorf, M. J.; Calchi Novati, S.; Dreizler, S.; Finet, F.; Glitrup, M.; Grundahl, F.; Harpsøe, K.; Hessman, F. V.; Hinse, T. C.; Hundertmark, M.; Liebig, C.; Maier, G.; Mancini, L.; Rahvar, S.; Ricci, D.; Scarpetta, G.; Skottfelt, J.; Southworth, J.; Surdej, J.; Zimmer, F.

In: Astronomy and Astrophysics, Vol. 547, A55, 30.10.2012.

Research output: Contribution to journalArticle

Bachelet, E, Fouqué, P, Han, C, Gould, A, Albrow, MD, Beaulieu, JP, Bertin, E, Bond, IA, Christie, GW, Heyrovský, D, Horne, K, Jørgensen, 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, Dominis Prester, D, Donatowicz, J, Greenhill, J, Kains, N, Kane, SR, Marquette, JB, 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, Kozłowski, S, Lee, CU, Monard, LAG, Muñoz, JA, Park, BG, 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, Harpsøe, 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 and Astrophysics, vol. 547, A55. https://doi.org/10.1051/0004-6361/201219765
Bachelet E, Fouqué P, Han C, Gould A, Albrow MD, Beaulieu JP et al. A brown dwarf orbiting an M-dwarf: MOA 2009-BLG-411L. Astronomy and Astrophysics. 2012 Oct 30;547. A55. https://doi.org/10.1051/0004-6361/201219765
Bachelet, E. ; Fouqué, P. ; Han, C. ; Gould, A. ; Albrow, M. D. ; Beaulieu, J. P. ; Bertin, E. ; Bond, I. A. ; Christie, G. W. ; Heyrovský, D. ; Horne, K. ; Jørgensen, U. G. ; Maoz, D. ; Mathiasen, M. ; Matsunaga, N. ; McCormick, J. ; Menzies, J. ; Nataf, D. ; Natusch, T. ; Oi, N. ; Renon, N. ; Tsapras, Y. ; Udalski, A. ; Yee, J. C. ; Batista, V. ; Bennett, D. P. ; Brillant, S. ; Caldwell, J. A R ; Cassan, A. ; Cole, A. ; Cook, K. H. ; Coutures, C. ; Dieters, S. ; Dominik, M. ; Dominis Prester, D. ; Donatowicz, J. ; Greenhill, J. ; Kains, N. ; Kane, S. R. ; Marquette, J. B. ; Martin, R. ; Pollard, K. R. ; Sahu, K. C. ; Street, R. A. ; Wambsganss, J. ; Williams, A. ; Zub, M. ; Bos, M. ; Dong, Subo ; Drummond, J. ; Gaudi, B. S. ; Graff, D. ; Janczak, J. ; Kaspi, S. ; Kozłowski, S. ; Lee, C. U. ; Monard, L. A G ; Muñoz, J. A. ; Park, B. G. ; Pogge, R. W. ; Polishook, D. ; Shporer, A. ; Abe, F. ; Botzler, C. S. ; Fukui, A. ; Furusawa, K. ; Hearnshaw, J. B. ; Itow, Y. ; Korpela, A. V. ; Ling, C. H. ; Masuda, K. ; Matsubara, Y. ; Miyake, N. ; Muraki, Y. ; Ohnishi, K. ; Rattenbury, N. J. ; Saito, To ; Sullivan, D. ; Sumi, T. ; Suzuki, D. ; Sweatman, W. L. ; Tristram, P. J. ; Wada, K. ; Allan, A. ; Bode, M. F. ; Bramich, D. M. ; Clay, N. ; Fraser, S. N. ; Hawkins, E. ; Kerins, E. ; Lister, T. A. ; Mottram, C. J. ; Saunders, E. S. ; Snodgrass, C. ; Steele, I. A. ; Wheatley, P. J. ; Bozza, V. ; Browne, P. ; Burgdorf, M. J. ; Calchi Novati, S. ; Dreizler, S. ; Finet, F. ; Glitrup, M. ; Grundahl, F. ; Harpsøe, K. ; Hessman, F. V. ; Hinse, T. C. ; Hundertmark, M. ; Liebig, C. ; Maier, G. ; Mancini, L. ; Rahvar, S. ; Ricci, D. ; Scarpetta, G. ; Skottfelt, J. ; Southworth, J. ; Surdej, J. ; Zimmer, F. / A brown dwarf orbiting an M-dwarf : MOA 2009-BLG-411L. In: Astronomy and Astrophysics. 2012 ; Vol. 547.
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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,α) 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 ·. 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 MS = 0.05 M· orbiting a primary M-star of mass MP = 0.18 M·. 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",
author = "E. Bachelet and P. Fouqu{\'e} 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. Heyrovsk{\'y} and K. Horne and J{\o}rgensen, {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 {Dominis Prester}, D. 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. Kozłowski and Lee, {C. U.} and Monard, {L. A G} and Mu{\~n}oz, {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. Harps{\o}e 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",
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month = "10",
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doi = "10.1051/0004-6361/201219765",
language = "English",
volume = "547",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
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TY - JOUR

T1 - A brown dwarf orbiting an M-dwarf

T2 - MOA 2009-BLG-411L

AU - Bachelet, E.

AU - Fouqué, 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 - Heyrovský, D.

AU - Horne, K.

AU - Jørgensen, 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 - Dominis Prester, D.

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 - Kozłowski, S.

AU - Lee, C. U.

AU - Monard, L. A G

AU - Muñoz, 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 - Harpsøe, 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 - 2012/10/30

Y1 - 2012/10/30

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,α) 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 ·. 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 MS = 0.05 M· orbiting a primary M-star of mass MP = 0.18 M·. 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,α) 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 ·. 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 MS = 0.05 M· orbiting a primary M-star of mass MP = 0.18 M·. 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

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U2 - 10.1051/0004-6361/201219765

DO - 10.1051/0004-6361/201219765

M3 - Article

VL - 547

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A55

ER -