The First Simultaneous Microlensing Observations by Two Space Telescopes: Spitzer and Swift Reveal a Brown Dwarf in Event OGLE-2015-BLG-1319

Shvartzvald, Y.; Li, Z.; Udalski, A.; Gould, A.; Sumi, T.; Street, R.A.; Calchi Novati, S.; Hundertmark, M.; Bozza, V.; Beichman, C.; Bryden, G.; Carey, S.; Drummond, J.; Fausnaugh, M.; Gaudi, B.S.; Henderson, C.B.; Tan, T.G.; Wibking, B.; Pogge, R.W.; Yee, J.C.; Zhu, W.; Tsapras, Y.; Bachelet, E.; Dominik, M.; Bramich, D.M.; Cassan, A.; Figuera Jaimes, R.; Horne, K.; Ranc, C.; Schmidt, R.; Snodgrass, C.; Wambsganss, J.; Steele, I.A.; Menzies, J.; Mao, S.; Poleski, R.; Pawlak, M.; Szymański, M.K.; Skowron, J.; Mróz, P.; Kozłowski, S.; Wyrzykowski, Ł.; Pietrukowicz, P.; Soszyński, I.; Ulaczyk, K.; Abe, F.; Asakura, Y.; Barry, R.K.; Bennett, D.P.; Bhattacharya, A.; Bond, I.A.; Freeman, M.; Hirao, Y.; Itow, Y.; Koshimoto, N.; Li, M.C.A.; Ling, C.H.; Masuda, K.; Fukui, A.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Nishioka, T.; Ohnishi, K.; Oyokawa, H.; Rattenbury, N.J.; To. Saito; Sharan, A.; Sullivan, D.J.; Suzuki, D.; Tristram, P.J.; Yonehara, A.; Jørgensen, U.G.; Burgdorf, M.J.; Ciceri, S.; D'Ago, G.; Evans, D.F.; Hinse, T.C.; Kains, N.; Kerins, E.; Korhonen, H.; Mancini, L.; Popovas, A.; Rabus, M.; Rahvar, S.; Scarpetta, G.; Skottfelt, J.; Southworth, J.; Peixinho, N.; Verma, P.; Sbarufatti, B.; Kennea, J.A.; Gehrels, N.

doi:10.3847/0004-637X/831/2/183

The First Simultaneous Microlensing Observations by Two Space Telescopes: Spitzer and Swift Reveal a Brown Dwarf in Event OGLE-2015-BLG-1319

Shvartzvald, Y.; Li, Z.; Udalski, A.; Gould, A.; Sumi, T.; Street, R.A.; Calchi Novati, S.; Hundertmark, M.; Bozza, V.; Beichman, C.; Bryden, G.; Carey, S.; Drummond, J.; Fausnaugh, M.; Gaudi, B.S.; Henderson, C.B.; Tan, T.G.; Wibking, B.; Pogge, R.W.; Yee, J.C.; Zhu, W.; Tsapras, Y.; Bachelet, E.; Dominik, M.; Bramich, D.M.; Cassan, A.; Figuera Jaimes, R.; Horne, K.; Ranc, C.; Schmidt, R.; Snodgrass, C.; Wambsganss, J.; Steele, I.A.; Menzies, J.; Mao, S.; Poleski, R.; Pawlak, M.; Szymański, M.K.; Skowron, J.; Mróz, P.; Kozłowski, S.; Wyrzykowski, Ł. ; Pietrukowicz, P.; Soszyński, I.; Ulaczyk, K.; Abe, F.; Asakura, Y.; Barry, R.K.; Bennett, D.P.; Bhattacharya, A.; Bond, I.A.; Freeman, M.; Hirao, Y.; Itow, Y.; Koshimoto, N.; Li, M.C.A.; Ling, C.H.; Masuda, K.; Fukui, A.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Nishioka, T.; Ohnishi, K.; Oyokawa, H.; Rattenbury, N.J.; To. Saito; Sharan, A.; Sullivan, D.J.; Suzuki, D.; Tristram, P.J.; Yonehara, A.; Jørgensen, U.G.; Burgdorf, M.J.; Ciceri...

Authors

Y. Shvartzvald

Z. Li

A. Udalski

A. Gould

T. Sumi

R.A. Street

S. Calchi Novati

M. Hundertmark

V. Bozza

C. Beichman

G. Bryden

S. Carey

J. Drummond

M. Fausnaugh

B.S. Gaudi

C.B. Henderson

T.G. Tan

B. Wibking

R.W. Pogge

J.C. Yee

W. Zhu

Y. Tsapras

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

R. Poleski

M. Pawlak

M.K. Szymański

J. Skowron

P. Mróz

S. Kozłowski

Ł. Wyrzykowski

P. Pietrukowicz

I. Soszyński

K. Ulaczyk

F. Abe

Y. Asakura

R.K. Barry

D.P. Bennett

A. Bhattacharya

I.A. Bond

M. Freeman

Y. Hirao

Y. Itow

N. Koshimoto

M.C.A. Li

C.H. Ling

K. Masuda

A. Fukui

Y. Matsubara

Y. Muraki

M. Nagakane

T. Nishioka

K. Ohnishi

H. Oyokawa

N.J. Rattenbury

To. Saito

A. Sharan

D.J. Sullivan

D. Suzuki

P.J. Tristram

A. Yonehara

U.G. Jørgensen

M.J. Burgdorf

S. Ciceri

G. D'Ago

D.F. Evans

T.C. Hinse

N. Kains

E. Kerins

H. Korhonen

L. Mancini

A. Popovas

M. Rabus

S. Rahvar

G. Scarpetta

J. Skottfelt

Dr John Taylor j.k.taylor@keele.ac.uk

N. Peixinho

P. Verma

B. Sbarufatti

J.A. Kennea

N. Gehrels

Abstract

Simultaneous observations of microlensing events from multiple locations allow for the breaking of degeneracies between the physical properties of the lensing system, specifically by exploring different regions of the lens plane and by directly measuring the "microlens parallax." We report the discovery of a 30–65M J brown dwarf orbiting a K dwarf in the microlensing event OGLE-2015-BLG-1319. The system is located at a distance of ~5 kpc toward the Galactic Bulge. The event was observed by several ground-based groups as well as by Spitzer and Swift, allowing a measurement of the physical properties. However, the event is still subject to an eight-fold degeneracy, in particular the well-known close-wide degeneracy, and thus the projected separation between the two lens components is either ~0.25 au or ~45 au. This is the first microlensing event observed by Swift, with the UVOT camera. We study the region of microlensing parameter space to which Swift is sensitive, finding that though Swift could not measure the microlens parallax with respect to ground-based observations for this event, it can be important for other events. Specifically, it is important for detecting nearby brown dwarfs and free-floating planets in high magnification events.

Citation

Shvartzvald, Y., Li, Z., Udalski, A., Gould, A., Sumi, T., Street, R., …Gehrels, N. (2016). The First Simultaneous Microlensing Observations by Two Space Telescopes: Spitzer and Swift Reveal a Brown Dwarf in Event OGLE-2015-BLG-1319. Astrophysical Journal, 831(2), Article 183. https://doi.org/10.3847/0004-637X/831/2/183

Journal Article Type	Article
Acceptance Date	Aug 24, 2016
Online Publication Date	Nov 7, 2016
Publication Date	Nov 10, 2016
Journal	Astrophysical Journal
Print ISSN	0004-637X
Publisher	American Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	831
Issue	2
Article Number	183
DOI	https://doi.org/10.3847/0004-637X/831/2/183
Keywords	binaries, general, brown dwarfs, Galaxy, bulge, gravitational lensing, micro
Publisher URL	https://doi.org/10.3847/0004-637X/831/2/183