MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary

R. A. Street; J. -Y. Choi; Y. Tsapras; C. Han; K. Furusawa; M. Hundertmark; A. Gould; T. Sumi; I. A. Bond; D. Wouters; R. Zellem; A. Udalski; C. Snodgrass; K. Horne; M. Dominik; P. Browne; N. Kains; D. M. Bramich; D. Bajek; I. A. Steele; S. Ipatov; F. Abe; D. P. Bennett; C. S. Botzler; P. Chote; M. Freeman; A. Fukui; P. Harris; Y. Itow; C. H. Ling; K. Masuda; Y. Matsubara; N. Miyake; Y. Muraki; T. Nagayama; S. Nishimaya; K. Ohnishi; N. Rattenbury; To. Saito; D. J. Sullivan; D. Suzuki; W. L. Sweatman; P. J. Tristram; K. Wada; P. C. M. Yock; M. K. Szymanski; M. Kubiak; G. Pietrzynski; I. Soszynski; R. Poleski; K. Ulaczyk; L. Wyrzykowski; J. Yee; S. Dong; I. -G. Shin; C. -U. Lee; J. Skowron; L. Andrade De Almeida; D. L. DePoy; B. S. Gaudi; L. -W. Hung; F. Jablonski; S. Kaspi; N. Klein; K. -H. Hwang; J. -R. Koo; D. Maoz; J. A. Munoz; R. W. Pogge; D. Polishhook; A. Shporer; J. McCormick; G. Christie; T. Natusch; B. Allen; J. Drummond; D. Moorhouse; G. Thornley; M. Knowler; M. Bos; G. Bolt; J. -P. Beaulieu; M. D. Albrow; V. Batista; S. Brillant; J. A. R. Caldwell; A. Cassan; A. Cole; E. Corrales; Ch. Coutures; S. Dieters; D. Dominis Prester; J. Donatowicz; P. Fouque; E. Bachelet; J. Greenhill; S. R. Kane; D. Kubas; J. -B. Marquette; R. Martin; J. Menzies; K. R. Pollard; K. C. Sahu; J. Wambsganss; A. Williams; M. Zub; K. A. Alsubai; V. Bozza; M. J. Burgdorf; S. Calchi Novati; P. Dodds; S. Dreizler; F. Finet; T. Gerner; S. Hardis; K. Harpsoe; F. Hessman; T. C. Hinse; U. G. Jorgensen; E. Kerins; C. Liebig; L. Mancini; M. Mathiasen; M. T. Penny; S. Proft; S. Rahvar; D. Ricci; G. Scarpetta; S. Schaefer; F. Schoenebeck; J. Southworth; J. Surdej

doi:10.1088/0004-637X/763/1/67

MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary

R. A. Street, J. -Y. Choi, Y. Tsapras, C. Han^*, K. Furusawa, M. Hundertmark, A. Gould, T. Sumi, I. A. Bond, D. Wouters, R. Zellem, A. Udalski, C. Snodgrass, K. Horne, M. Dominik, P. Browne, N. Kains, D. M. Bramich, D. Bajek, I. A. SteeleS. Ipatov, F. Abe, D. P. Bennett, C. S. Botzler, P. Chote, M. Freeman, A. Fukui, P. Harris, Y. Itow, C. H. Ling, K. Masuda, Y. Matsubara, N. Miyake, Y. Muraki, T. Nagayama, S. Nishimaya, K. Ohnishi, N. Rattenbury, To. Saito, D. J. Sullivan, D. Suzuki, W. L. Sweatman, P. J. Tristram, K. Wada, P. C. M. Yock, M. K. Szymanski, M. Kubiak, G. Pietrzynski, I. Soszynski, R. Poleski, K. Ulaczyk, L. Wyrzykowski, J. Yee, S. Dong, I. -G. Shin, C. -U. Lee, J. Skowron, L. Andrade De Almeida, D. L. DePoy, B. S. Gaudi, L. -W. Hung, F. Jablonski, S. Kaspi, N. Klein, K. -H. Hwang, J. -R. Koo, D. Maoz, J. A. Munoz, R. W. Pogge, D. Polishhook, A. Shporer, J. McCormick, G. Christie, T. Natusch, B. Allen, J. Drummond, D. Moorhouse, G. Thornley, M. Knowler, M. Bos, G. Bolt, J. -P. Beaulieu, M. D. Albrow, V. Batista, S. Brillant, J. A. R. Caldwell, A. Cassan, A. Cole, E. Corrales, Ch. Coutures, S. Dieters, D. Dominis Prester, J. Donatowicz, P. Fouque, E. Bachelet, J. Greenhill, S. R. Kane, D. Kubas, J. -B. Marquette, R. Martin, J. Menzies, K. R. Pollard, K. C. Sahu, J. Wambsganss, A. Williams, M. Zub, K. A. Alsubai, V. Bozza, M. J. Burgdorf, S. Calchi Novati, P. Dodds, S. Dreizler, F. Finet, T. Gerner, S. Hardis, K. Harpsoe, F. Hessman, T. C. Hinse, U. G. Jorgensen, E. Kerins, C. Liebig, L. Mancini, M. Mathiasen, M. T. Penny, S. Proft, S. Rahvar, D. Ricci, G. Scarpetta, S. Schaefer, F. Schoenebeck, J. Southworth, J. Surdej

^*Corresponding author for this work

School of Physics and Astronomy

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

Abstract

We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because the source was previously known to be photometrically variable. Analyzing the pre-event source light curve, we demonstrate that it is an irregular variable over timescales >200 days. Its dereddened color, (V - I)(S),(0), is 1.221 +/- 0.051 mag, and from our lens model we derive a source radius of 14.7 +/- 1.3 R-circle dot, suggesting that it is a red giant star. We initially explored a number of purely microlensing models for the event but found a residual gradient in the data taken prior to and after the event. This is likely to be due to the variability of the source rather than part of the lensing event, so we incorporated a slope parameter in our model in order to derive the true parameters of the lensing system. We find that the lensing system has a mass ratio of q = 0.0654 +/- 0.0006. The Einstein crossing time of the event, t(E) = 44.3 +/- 0.1 days, was sufficiently long that the light curve exhibited parallax effects. In addition, the source trajectory relative to the large caustic structure allowed the orbital motion of the lens system to be detected. Combining the parallax with the Einstein radius, we were able to derive the distance to the lens, D-L = 2.8 +/- 0.4 kpc, and the masses of the lensing objects. The primary of the lens is an M-dwarf with M-L,M-1 = 0.16 +/- 0.03 M-circle dot, while the companion has M-L,M-2 = 11.0 +/- 2.0 M-J, putting it in the boundary zone between planets and brown dwarfs.

Original language	English
Article number	67
Number of pages	13
Journal	Astrophysical Journal
Volume	763
Issue number	1
DOIs	https://doi.org/10.1088/0004-637X/763/1/67
Publication status	Published - 20 Jan 2013

Keywords

Brown dwarfs
Gravitational lensing: micro
Planetary systems
Planets and satellites: formation
Planets and satellites: general
Techniques: photometric
Gravitational lensing experiment
Difference image-analysis
Gas giant planets
Microlensing events
Galactic bulge
Variable-stars
Minimum mass
Variability
Evolution

Access to Document

10.1088/0004-637X/763/1/67

street2013astrosphysj67
© 2013. The American Astronomical Society. All rights reserved.
Final published version, 3.92 MB

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

Street, R. A., Choi, J. .-Y., Tsapras, Y., Han, C., Furusawa, K., Hundertmark, M., Gould, A., Sumi, T., Bond, I. A., Wouters, D., Zellem, R., Udalski, A., Snodgrass, C., Horne, K., Dominik, M., Browne, P., Kains, N., Bramich, D. M., Bajek, D., ... Surdej, J. (2013). MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary. Astrophysical Journal, 763(1), Article 67. https://doi.org/10.1088/0004-637X/763/1/67

@article{4c94a11c14d5423aa2ecc7350c588071,

title = "MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary",

abstract = "We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because the source was previously known to be photometrically variable. Analyzing the pre-event source light curve, we demonstrate that it is an irregular variable over timescales >200 days. Its dereddened color, (V - I)(S),(0), is 1.221 +/- 0.051 mag, and from our lens model we derive a source radius of 14.7 +/- 1.3 R-circle dot, suggesting that it is a red giant star. We initially explored a number of purely microlensing models for the event but found a residual gradient in the data taken prior to and after the event. This is likely to be due to the variability of the source rather than part of the lensing event, so we incorporated a slope parameter in our model in order to derive the true parameters of the lensing system. We find that the lensing system has a mass ratio of q = 0.0654 +/- 0.0006. The Einstein crossing time of the event, t(E) = 44.3 +/- 0.1 days, was sufficiently long that the light curve exhibited parallax effects. In addition, the source trajectory relative to the large caustic structure allowed the orbital motion of the lens system to be detected. Combining the parallax with the Einstein radius, we were able to derive the distance to the lens, D-L = 2.8 +/- 0.4 kpc, and the masses of the lensing objects. The primary of the lens is an M-dwarf with M-L,M-1 = 0.16 +/- 0.03 M-circle dot, while the companion has M-L,M-2 = 11.0 +/- 2.0 M-J, putting it in the boundary zone between planets and brown dwarfs.",

keywords = "Brown dwarfs, Gravitational lensing: micro, Planetary systems, Planets and satellites: formation, Planets and satellites: general, Techniques: photometric, Gravitational lensing experiment, Difference image-analysis, Gas giant planets, Microlensing events, Galactic bulge, Variable-stars, Minimum mass, Variability, Evolution",

author = "Street, {R. A.} and Choi, {J. -Y.} and Y. Tsapras and C. Han and K. Furusawa and M. Hundertmark and A. Gould and T. Sumi and Bond, {I. A.} and D. Wouters and R. Zellem and A. Udalski and C. Snodgrass and K. Horne and M. Dominik and P. Browne and N. Kains and Bramich, {D. M.} and D. Bajek and Steele, {I. A.} and S. Ipatov and F. Abe and Bennett, {D. P.} and Botzler, {C. S.} and P. Chote and M. Freeman and A. Fukui and P. Harris and Y. Itow and Ling, {C. H.} and K. Masuda and Y. Matsubara and N. Miyake and Y. Muraki and T. Nagayama and S. Nishimaya and K. Ohnishi and N. Rattenbury and To. Saito and Sullivan, {D. J.} and D. Suzuki and Sweatman, {W. L.} and Tristram, {P. J.} and K. Wada and Yock, {P. C. M.} and Szymanski, {M. K.} and M. Kubiak and G. Pietrzynski and I. Soszynski and R. Poleski and K. Ulaczyk and L. Wyrzykowski and J. Yee and S. Dong and Shin, {I. -G.} and Lee, {C. -U.} and J. Skowron and {Andrade De Almeida}, L. and DePoy, {D. L.} and Gaudi, {B. S.} and Hung, {L. -W.} and F. Jablonski and S. Kaspi and N. Klein and Hwang, {K. -H.} and Koo, {J. -R.} and D. Maoz and Munoz, {J. A.} and Pogge, {R. W.} and D. Polishhook and A. Shporer and J. McCormick and G. Christie and T. Natusch and B. Allen and J. Drummond and D. Moorhouse and G. Thornley and M. Knowler and M. Bos and G. Bolt and Beaulieu, {J. -P.} and Albrow, {M. D.} and V. Batista and S. Brillant and Caldwell, {J. A. R.} and A. Cassan and A. Cole and E. Corrales and Ch. Coutures and S. Dieters and Prester, {D. Dominis} and J. Donatowicz and P. Fouque and E. Bachelet and J. Greenhill and Kane, {S. R.} and D. Kubas and Marquette, {J. -B.} and R. Martin and J. Menzies and Pollard, {K. R.} and Sahu, {K. C.} and J. Wambsganss and A. Williams and M. Zub and Alsubai, {K. A.} and V. Bozza and Burgdorf, {M. J.} and {Calchi Novati}, S. and P. Dodds and S. Dreizler and F. Finet and T. Gerner and S. Hardis and K. Harpsoe and F. Hessman and Hinse, {T. C.} and Jorgensen, {U. G.} and E. Kerins and C. Liebig and L. Mancini and M. Mathiasen and Penny, {M. T.} and S. Proft and S. Rahvar and D. Ricci and G. Scarpetta and S. Schaefer and F. Schoenebeck and J. Southworth and J. Surdej",

year = "2013",

month = jan,

day = "20",

doi = "10.1088/0004-637X/763/1/67",

language = "English",

volume = "763",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "1",

}

Street, RA, Choi, J-Y, Tsapras, Y, Han, C, Furusawa, K, Hundertmark, M, Gould, A, Sumi, T, Bond, IA, Wouters, D, Zellem, R, Udalski, A, Snodgrass, C, Horne, K , Dominik, M, Browne, P, Kains, N, Bramich, DM, Bajek, D, Steele, IA, Ipatov, S, Abe, F, Bennett, DP, Botzler, CS, Chote, P, Freeman, M, Fukui, A, Harris, P, Itow, Y, Ling, CH, Masuda, K, Matsubara, Y, Miyake, N, Muraki, Y, Nagayama, T, Nishimaya, S, Ohnishi, K, Rattenbury, N, Saito, T, Sullivan, DJ, Suzuki, D, Sweatman, WL, Tristram, PJ, Wada, K, Yock, PCM, Szymanski, MK, Kubiak, M, Pietrzynski, G, Soszynski, I, Poleski, R, Ulaczyk, K, Wyrzykowski, L, Yee, J, Dong, S, Shin, I-G, Lee, C-U, Skowron, J, Andrade De Almeida, L, DePoy, DL, Gaudi, BS, Hung, L-W, Jablonski, F, Kaspi, S, Klein, N, Hwang, K-H, Koo, J-R, Maoz, D, Munoz, JA, Pogge, RW, Polishhook, D, Shporer, A, McCormick, J, Christie, G, Natusch, T, Allen, B, Drummond, J, Moorhouse, D, Thornley, G, Knowler, M, Bos, M, Bolt, G, Beaulieu, J-P, Albrow, MD, Batista, V, Brillant, S, Caldwell, JAR, Cassan, A, Cole, A, Corrales, E, Coutures, C, Dieters, S, Prester, DD, Donatowicz, J, Fouque, P, Bachelet, E, Greenhill, J, Kane, SR, Kubas, D, Marquette, J-B, Martin, R, Menzies, J, Pollard, KR, Sahu, KC, Wambsganss, J, Williams, A, Zub, M, Alsubai, KA, Bozza, V, Burgdorf, MJ, Calchi Novati, S, Dodds, P, Dreizler, S, Finet, F, Gerner, T, Hardis, S, Harpsoe, K, Hessman, F, Hinse, TC, Jorgensen, UG, Kerins, E, Liebig, C, Mancini, L, Mathiasen, M, Penny, MT, Proft, S, Rahvar, S, Ricci, D, Scarpetta, G, Schaefer, S, Schoenebeck, F, Southworth, J & Surdej, J 2013, 'MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary', Astrophysical Journal, vol. 763, no. 1, 67. https://doi.org/10.1088/0004-637X/763/1/67

TY - JOUR

T1 - MOA-2010-BLG-073L

T2 - An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary

AU - Street, R. A.

AU - Choi, J. -Y.

AU - Tsapras, Y.

AU - Han, C.

AU - Furusawa, K.

AU - Hundertmark, M.

AU - Gould, A.

AU - Sumi, T.

AU - Bond, I. A.

AU - Wouters, D.

AU - Zellem, R.

AU - Udalski, A.

AU - Snodgrass, C.

AU - Horne, K.

AU - Dominik, M.

AU - Browne, P.

AU - Kains, N.

AU - Bramich, D. M.

AU - Bajek, D.

AU - Steele, I. A.

AU - Ipatov, S.

AU - Abe, F.

AU - Bennett, D. P.

AU - Botzler, C. S.

AU - Chote, P.

AU - Freeman, M.

AU - Fukui, A.

AU - Harris, P.

AU - Itow, Y.

AU - Ling, C. H.

AU - Masuda, K.

AU - Matsubara, Y.

AU - Miyake, N.

AU - Muraki, Y.

AU - Nagayama, T.

AU - Nishimaya, S.

AU - Ohnishi, K.

AU - Rattenbury, N.

AU - Saito, To.

AU - Sullivan, D. J.

AU - Suzuki, D.

AU - Sweatman, W. L.

AU - Tristram, P. J.

AU - Wada, K.

AU - Yock, P. C. M.

AU - Szymanski, M. K.

AU - Kubiak, M.

AU - Pietrzynski, G.

AU - Soszynski, I.

AU - Poleski, R.

AU - Ulaczyk, K.

AU - Wyrzykowski, L.

AU - Yee, J.

AU - Dong, S.

AU - Shin, I. -G.

AU - Lee, C. -U.

AU - Skowron, J.

AU - Andrade De Almeida, L.

AU - DePoy, D. L.

AU - Gaudi, B. S.

AU - Hung, L. -W.

AU - Jablonski, F.

AU - Kaspi, S.

AU - Klein, N.

AU - Hwang, K. -H.

AU - Koo, J. -R.

AU - Maoz, D.

AU - Munoz, J. A.

AU - Pogge, R. W.

AU - Polishhook, D.

AU - Shporer, A.

AU - McCormick, J.

AU - Christie, G.

AU - Natusch, T.

AU - Allen, B.

AU - Drummond, J.

AU - Moorhouse, D.

AU - Thornley, G.

AU - Knowler, M.

AU - Bos, M.

AU - Bolt, G.

AU - Beaulieu, J. -P.

AU - Albrow, M. D.

AU - Batista, V.

AU - Brillant, S.

AU - Caldwell, J. A. R.

AU - Cassan, A.

AU - Cole, A.

AU - Corrales, E.

AU - Coutures, Ch.

AU - Dieters, S.

AU - Prester, D. Dominis

AU - Donatowicz, J.

AU - Fouque, P.

AU - Bachelet, E.

AU - Greenhill, J.

AU - Kane, S. R.

AU - Kubas, D.

AU - Marquette, J. -B.

AU - Martin, R.

AU - Menzies, J.

AU - Pollard, K. R.

AU - Sahu, K. C.

AU - Wambsganss, J.

AU - Williams, A.

AU - Zub, M.

AU - Alsubai, K. A.

AU - Bozza, V.

AU - Burgdorf, M. J.

AU - Calchi Novati, S.

AU - Dodds, P.

AU - Dreizler, S.

AU - Finet, F.

AU - Gerner, T.

AU - Hardis, S.

AU - Harpsoe, K.

AU - Hessman, F.

AU - Hinse, T. C.

AU - Jorgensen, U. G.

AU - Kerins, E.

AU - Liebig, C.

AU - Mancini, L.

AU - Mathiasen, M.

AU - Penny, M. T.

AU - Proft, S.

AU - Rahvar, S.

AU - Ricci, D.

AU - Scarpetta, G.

AU - Schaefer, S.

AU - Schoenebeck, F.

AU - Southworth, J.

AU - Surdej, J.

PY - 2013/1/20

Y1 - 2013/1/20

N2 - We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because the source was previously known to be photometrically variable. Analyzing the pre-event source light curve, we demonstrate that it is an irregular variable over timescales >200 days. Its dereddened color, (V - I)(S),(0), is 1.221 +/- 0.051 mag, and from our lens model we derive a source radius of 14.7 +/- 1.3 R-circle dot, suggesting that it is a red giant star. We initially explored a number of purely microlensing models for the event but found a residual gradient in the data taken prior to and after the event. This is likely to be due to the variability of the source rather than part of the lensing event, so we incorporated a slope parameter in our model in order to derive the true parameters of the lensing system. We find that the lensing system has a mass ratio of q = 0.0654 +/- 0.0006. The Einstein crossing time of the event, t(E) = 44.3 +/- 0.1 days, was sufficiently long that the light curve exhibited parallax effects. In addition, the source trajectory relative to the large caustic structure allowed the orbital motion of the lens system to be detected. Combining the parallax with the Einstein radius, we were able to derive the distance to the lens, D-L = 2.8 +/- 0.4 kpc, and the masses of the lensing objects. The primary of the lens is an M-dwarf with M-L,M-1 = 0.16 +/- 0.03 M-circle dot, while the companion has M-L,M-2 = 11.0 +/- 2.0 M-J, putting it in the boundary zone between planets and brown dwarfs.

AB - We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because the source was previously known to be photometrically variable. Analyzing the pre-event source light curve, we demonstrate that it is an irregular variable over timescales >200 days. Its dereddened color, (V - I)(S),(0), is 1.221 +/- 0.051 mag, and from our lens model we derive a source radius of 14.7 +/- 1.3 R-circle dot, suggesting that it is a red giant star. We initially explored a number of purely microlensing models for the event but found a residual gradient in the data taken prior to and after the event. This is likely to be due to the variability of the source rather than part of the lensing event, so we incorporated a slope parameter in our model in order to derive the true parameters of the lensing system. We find that the lensing system has a mass ratio of q = 0.0654 +/- 0.0006. The Einstein crossing time of the event, t(E) = 44.3 +/- 0.1 days, was sufficiently long that the light curve exhibited parallax effects. In addition, the source trajectory relative to the large caustic structure allowed the orbital motion of the lens system to be detected. Combining the parallax with the Einstein radius, we were able to derive the distance to the lens, D-L = 2.8 +/- 0.4 kpc, and the masses of the lensing objects. The primary of the lens is an M-dwarf with M-L,M-1 = 0.16 +/- 0.03 M-circle dot, while the companion has M-L,M-2 = 11.0 +/- 2.0 M-J, putting it in the boundary zone between planets and brown dwarfs.

KW - Brown dwarfs

KW - Gravitational lensing: micro

KW - Planetary systems

KW - Planets and satellites: formation

KW - Planets and satellites: general

KW - Techniques: photometric

KW - Gravitational lensing experiment

KW - Difference image-analysis

KW - Gas giant planets

KW - Microlensing events

KW - Galactic bulge

KW - Variable-stars

KW - Minimum mass

KW - Variability

KW - Evolution

U2 - 10.1088/0004-637X/763/1/67

DO - 10.1088/0004-637X/763/1/67

M3 - Article

SN - 0004-637X

VL - 763

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1

M1 - 67

ER -

MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary

Abstract

Keywords

Access to Document

Fingerprint

Projects

Astrophysics at St Andrews:2012 - 2014: Astrophysics at St Andrews: 2012 - 2014

Cite this