OGLE-2015-BLG-0479LA,B

BINARY GRAVITATIONAL MICROLENS CHARACTERIZED by SIMULTANEOUS GROUND-BASED and SPACE-BASED OBSERVATIONS

C. Han, A. Udalski, A. Gould, Wei Zhu, R. A. Street, J. C. Yee, C. Beichman, C. Bryden, S. Calchi Novati, S. Carey, M. Fausnaugh, B. S. Gaudi, Calen B. Henderson, Y. Shvartzvald, B. Wibking, M. K. Szymański, I. Soszyński, J. Skowron, P. Mróz, R. Poleski & 43 others P. Pietrukowicz, S. Kozłowski, K. Ulaczyk, Wyrzykowski, M. Pawlak, Y. Tsapras, M. Hundertmark, E. Bachelet, M. Dominik, D. M. Bramich, A. Cassan, R. Figuera Jaimes, K. Horne, C. Ranc, R. Schmidt, C. Snodgrass, J. Wambsganss, I. A. Steele, J. Menzies, S. Mao, V. Bozza, U. G. Jørgensen, Khalid Al-Subai, S. Ciceri, G. D'Ago, T. Haugbølle, F. V. Hessman, T. C. Hinse, D. Juncher, H. Korhonen, L. Mancini, A. Popovas, M. Rabus, S. Rahvar, G. Scarpetta, J. Skottfelt, J. Southworth, D. Starkey, J. Surdej, O. Wertz, M. Zarucki, R. W. Pogge, D. L. DePoy

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the Spitzer Space Telescope. The light curves seen from the ground and from space exhibit a time offset of ∼13 days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses of ∼1.0 M and ∼0.9 M located at a distance of ∼3 kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also observed by Spitzer, we find that the interpretation of OGLE-2015-BLG-0479 does not suffer from the degeneracy between (±, ±) and (±, ∓) solutions, confirming that the four-fold parallax degeneracy in single-lens events collapses into the two-fold degeneracy for the general case of binary-lens events. The location of the blend in the color-magnitude diagram is consistent with the lens properties, suggesting that the blend is the lens itself. The blend is bright enough for spectroscopy and thus this possibility can be checked from future follow-up observations.

Original languageEnglish
Article number53
JournalAstrophysical Journal
Volume828
Issue number1
DOIs
Publication statusPublished - 1 Sep 2016

Fingerprint

lenses
parallax
fold
diagram
spectroscopy
light curve
alkalies
modeling
Space Infrared Telescope Facility
color-magnitude diagram
spikes
analysis
stars
orbitals
radii
effect
parameter

Keywords

  • binaries: general
  • gravitational lensing: micro

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

OGLE-2015-BLG-0479LA,B : BINARY GRAVITATIONAL MICROLENS CHARACTERIZED by SIMULTANEOUS GROUND-BASED and SPACE-BASED OBSERVATIONS. / Han, C.; Udalski, A.; Gould, A.; Zhu, Wei; Street, R. A.; Yee, J. C.; Beichman, C.; Bryden, C.; Novati, S. Calchi; Carey, S.; Fausnaugh, M.; Gaudi, B. S.; Henderson, Calen B.; Shvartzvald, Y.; Wibking, B.; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R.; Pietrukowicz, P.; Kozłowski, S.; Ulaczyk, K.; Wyrzykowski; Pawlak, M.; Tsapras, Y.; Hundertmark, M.; Bachelet, E.; Dominik, M.; Bramich, D. M.; Cassan, A.; Jaimes, R. Figuera; Horne, K.; Ranc, C.; Schmidt, R.; Snodgrass, C.; Wambsganss, J.; Steele, I. A.; Menzies, J.; Mao, S.; Bozza, V.; Jørgensen, U. G.; Al-Subai, Khalid; Ciceri, S.; D'Ago, G.; Haugbølle, T.; Hessman, F. V.; Hinse, T. C.; Juncher, D.; Korhonen, H.; Mancini, L.; Popovas, A.; Rabus, M.; Rahvar, S.; Scarpetta, G.; Skottfelt, J.; Southworth, J.; Starkey, D.; Surdej, J.; Wertz, O.; Zarucki, M.; Pogge, R. W.; DePoy, D. L.

In: Astrophysical Journal, Vol. 828, No. 1, 53, 01.09.2016.

Research output: Contribution to journalArticle

Han, C, Udalski, A, Gould, A, Zhu, W, Street, RA, Yee, JC, Beichman, C, Bryden, C, Novati, SC, Carey, S, Fausnaugh, M, Gaudi, BS, Henderson, CB, Shvartzvald, Y, Wibking, B, Szymański, MK, Soszyński, I, Skowron, J, Mróz, P, Poleski, R, Pietrukowicz, P, Kozłowski, S, Ulaczyk, K, Wyrzykowski, Pawlak, M, Tsapras, Y, Hundertmark, M, Bachelet, E, Dominik, M, Bramich, DM, Cassan, A, Jaimes, RF, Horne, K, Ranc, C, Schmidt, R, Snodgrass, C, Wambsganss, J, Steele, IA, Menzies, J, Mao, S, Bozza, V, Jørgensen, UG, Al-Subai, K, Ciceri, S, D'Ago, G, Haugbølle, T, Hessman, FV, Hinse, TC, Juncher, D, Korhonen, H, Mancini, L, Popovas, A, Rabus, M, Rahvar, S, Scarpetta, G, Skottfelt, J, Southworth, J, Starkey, D, Surdej, J, Wertz, O, Zarucki, M, Pogge, RW & DePoy, DL 2016, 'OGLE-2015-BLG-0479LA,B: BINARY GRAVITATIONAL MICROLENS CHARACTERIZED by SIMULTANEOUS GROUND-BASED and SPACE-BASED OBSERVATIONS', Astrophysical Journal, vol. 828, no. 1, 53. https://doi.org/10.3847/0004-637X/828/1/53
Han, C. ; Udalski, A. ; Gould, A. ; Zhu, Wei ; Street, R. A. ; Yee, J. C. ; Beichman, C. ; Bryden, C. ; Novati, S. Calchi ; Carey, S. ; Fausnaugh, M. ; Gaudi, B. S. ; Henderson, Calen B. ; Shvartzvald, Y. ; Wibking, B. ; Szymański, M. K. ; Soszyński, I. ; Skowron, J. ; Mróz, P. ; Poleski, R. ; Pietrukowicz, P. ; Kozłowski, S. ; Ulaczyk, K. ; Wyrzykowski ; Pawlak, M. ; Tsapras, Y. ; Hundertmark, M. ; Bachelet, E. ; Dominik, M. ; Bramich, D. M. ; Cassan, A. ; Jaimes, R. Figuera ; Horne, K. ; Ranc, C. ; Schmidt, R. ; Snodgrass, C. ; Wambsganss, J. ; Steele, I. A. ; Menzies, J. ; Mao, S. ; Bozza, V. ; Jørgensen, U. G. ; Al-Subai, Khalid ; Ciceri, S. ; D'Ago, G. ; Haugbølle, T. ; Hessman, F. V. ; Hinse, T. C. ; Juncher, D. ; Korhonen, H. ; Mancini, L. ; Popovas, A. ; Rabus, M. ; Rahvar, S. ; Scarpetta, G. ; Skottfelt, J. ; Southworth, J. ; Starkey, D. ; Surdej, J. ; Wertz, O. ; Zarucki, M. ; Pogge, R. W. ; DePoy, D. L. / OGLE-2015-BLG-0479LA,B : BINARY GRAVITATIONAL MICROLENS CHARACTERIZED by SIMULTANEOUS GROUND-BASED and SPACE-BASED OBSERVATIONS. In: Astrophysical Journal. 2016 ; Vol. 828, No. 1.
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abstract = "We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the Spitzer Space Telescope. The light curves seen from the ground and from space exhibit a time offset of ∼13 days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses of ∼1.0 M⊙ and ∼0.9 M⊙ located at a distance of ∼3 kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also observed by Spitzer, we find that the interpretation of OGLE-2015-BLG-0479 does not suffer from the degeneracy between (±, ±) and (±, ∓) solutions, confirming that the four-fold parallax degeneracy in single-lens events collapses into the two-fold degeneracy for the general case of binary-lens events. The location of the blend in the color-magnitude diagram is consistent with the lens properties, suggesting that the blend is the lens itself. The blend is bright enough for spectroscopy and thus this possibility can be checked from future follow-up observations.",
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author = "C. Han and A. Udalski and A. Gould and Wei Zhu and Street, {R. A.} and Yee, {J. C.} and C. Beichman and C. Bryden and Novati, {S. Calchi} and S. Carey and M. Fausnaugh and Gaudi, {B. S.} and Henderson, {Calen B.} and Y. Shvartzvald and B. Wibking and Szymański, {M. K.} and I. Soszyński and J. Skowron and P. Mr{\'o}z and R. Poleski and P. Pietrukowicz and S. Kozłowski and K. Ulaczyk and Wyrzykowski and M. Pawlak and Y. Tsapras and M. Hundertmark and E. Bachelet and M. Dominik and Bramich, {D. M.} and A. Cassan and Jaimes, {R. Figuera} and K. Horne and C. Ranc and R. Schmidt and C. Snodgrass and J. Wambsganss and Steele, {I. A.} and J. Menzies and S. Mao and V. Bozza and J{\o}rgensen, {U. G.} and Khalid Al-Subai and S. Ciceri and G. D'Ago and T. Haugb{\o}lle and Hessman, {F. V.} and Hinse, {T. C.} and D. Juncher and H. Korhonen and L. Mancini and A. Popovas and M. Rabus and S. Rahvar and G. Scarpetta and J. Skottfelt and J. Southworth and D. Starkey and J. Surdej and O. Wertz and M. Zarucki and Pogge, {R. W.} and DePoy, {D. L.}",
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TY - JOUR

T1 - OGLE-2015-BLG-0479LA,B

T2 - BINARY GRAVITATIONAL MICROLENS CHARACTERIZED by SIMULTANEOUS GROUND-BASED and SPACE-BASED OBSERVATIONS

AU - Han, C.

AU - Udalski, A.

AU - Gould, A.

AU - Zhu, Wei

AU - Street, R. A.

AU - Yee, J. C.

AU - Beichman, C.

AU - Bryden, C.

AU - Novati, S. Calchi

AU - Carey, S.

AU - Fausnaugh, M.

AU - Gaudi, B. S.

AU - Henderson, Calen B.

AU - Shvartzvald, Y.

AU - Wibking, B.

AU - Szymański, M. K.

AU - Soszyński, I.

AU - Skowron, J.

AU - Mróz, P.

AU - Poleski, R.

AU - Pietrukowicz, P.

AU - Kozłowski, S.

AU - Ulaczyk, K.

AU - Wyrzykowski,

AU - Pawlak, M.

AU - Tsapras, Y.

AU - Hundertmark, M.

AU - Bachelet, E.

AU - Dominik, M.

AU - Bramich, D. M.

AU - Cassan, A.

AU - Jaimes, R. Figuera

AU - Horne, K.

AU - Ranc, C.

AU - Schmidt, R.

AU - Snodgrass, C.

AU - Wambsganss, J.

AU - Steele, I. A.

AU - Menzies, J.

AU - Mao, S.

AU - Bozza, V.

AU - Jørgensen, U. G.

AU - Al-Subai, Khalid

AU - Ciceri, S.

AU - D'Ago, G.

AU - Haugbølle, T.

AU - Hessman, F. V.

AU - Hinse, T. C.

AU - Juncher, D.

AU - Korhonen, H.

AU - Mancini, L.

AU - Popovas, A.

AU - Rabus, M.

AU - Rahvar, S.

AU - Scarpetta, G.

AU - Skottfelt, J.

AU - Southworth, J.

AU - Starkey, D.

AU - Surdej, J.

AU - Wertz, O.

AU - Zarucki, M.

AU - Pogge, R. W.

AU - DePoy, D. L.

PY - 2016/9/1

Y1 - 2016/9/1

N2 - We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the Spitzer Space Telescope. The light curves seen from the ground and from space exhibit a time offset of ∼13 days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses of ∼1.0 M⊙ and ∼0.9 M⊙ located at a distance of ∼3 kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also observed by Spitzer, we find that the interpretation of OGLE-2015-BLG-0479 does not suffer from the degeneracy between (±, ±) and (±, ∓) solutions, confirming that the four-fold parallax degeneracy in single-lens events collapses into the two-fold degeneracy for the general case of binary-lens events. The location of the blend in the color-magnitude diagram is consistent with the lens properties, suggesting that the blend is the lens itself. The blend is bright enough for spectroscopy and thus this possibility can be checked from future follow-up observations.

AB - We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the Spitzer Space Telescope. The light curves seen from the ground and from space exhibit a time offset of ∼13 days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses of ∼1.0 M⊙ and ∼0.9 M⊙ located at a distance of ∼3 kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also observed by Spitzer, we find that the interpretation of OGLE-2015-BLG-0479 does not suffer from the degeneracy between (±, ±) and (±, ∓) solutions, confirming that the four-fold parallax degeneracy in single-lens events collapses into the two-fold degeneracy for the general case of binary-lens events. The location of the blend in the color-magnitude diagram is consistent with the lens properties, suggesting that the blend is the lens itself. The blend is bright enough for spectroscopy and thus this possibility can be checked from future follow-up observations.

KW - binaries: general

KW - gravitational lensing: micro

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