2013The Astrophysical JournalOpen access

MICROLENSING DISCOVERY OF A POPULATION OF VERY TIGHT, VERY LOW MASS BINARY BROWN DWARFS

J.-Y. Choi, Cheongho Han, A. Udalski, T. Sumi, B. Scott Gaudi, Andrew Gould, D. P. Bennett, M. Dominik, Jean‐Philippe Beaulieu, Y. Tsapras, V. Bozza, F. Abe, I. A. Bond, C. S. Botzler, P. Chote, M. Freeman, Akihiko Fukui, K. Furusawa, Y. Itow, C. H. Ling, K. Masuda, Y. Matsubara, N. Miyake, Y. Muraki, Koji Ohnishi, Nicholas J. Rattenbury, To. Saito, D. J. Sullivan, K. Suzuki, W. L. Sweatman, Daisuke Suzuki, S. Takino, P. J. Tristram, K. Wada, P. C. M. Yock, M. K. Szymański, M. Kubiak, G. Pietrzyński, I. Soszyński, J. Skowron, S. Kozłowski, R. Poleski, K. Ulaczyk, Ł. Wyrzykowski, P. Pietrukowicz, L. A. Almeida, D. L. DePoy, Subo Dong, E. Gorbikov, F. Jablonski, Calen B. Henderson, Kyu‐Ha Hwang, J. Janczak, Youn Kil Jung, S. Kaspi, Chung‐Uk Lee, Uri Malamud, D. Maoz, D. McGregor, J. A. Muñoz, B.-G. Park, H. Park, Richard W. Pogge, Yossi Shvartzvald, In-Gu Shin, Jennifer C. Yee, K. A. Alsubai, P. Browne, M. Burgdorf, S. Calchi Novati, P. Dodds, X.-S. Fang, F. Finet, M. Glitrup, F. Grundahl, S.-H. Gu, S. Hardis, K. Harpsøe, T. C. Hinse, A. Hornstrup, M. Hundertmark, J. Jessen‐Hansen, U. G. Jrgensen, N. Kains, E. Kerins, C. Liebig, Mikkel N. Lund, M. Lundkvist, G. Maier, L. Mancini, M. Mathiasen, Matthew T. Penny, S. Rahvar, D. Ricci, G. Scarpetta, J. Skottfelt, C. Snodgrass, J. Southworth, J. Surdej, J. Tregloan-Reed, J. Wambsganß, O. Wertz, F. Zimmer, Michael D. Albrow, E. Bachelet, V. Batista, S. Brillant, A. Cassan, Andrew A. Cole, C. Coutures, S. Dieters, D. Dominis Prester, J. Donatowicz, P. Fouqué, J. Greenhill, D. Kubas, J. B. Marquette, J. W. Menzies, K. C. Sahu, M. Zub, D. M. Bramich, K. Horne, I. A. Steele, R. A. Street

Open full text 51 citations

Abstract

Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs (BDs) are poorly understood. The multiplicity properties and minimum mass of the BD mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 M ☉ and 0.034 M ☉ , and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field BD binaries known. The discovery of a population of such binaries indicates that BD binaries can robustly form at least down to masses of ∼0.02 M ☉ . Future microlensing surveys will measure a mass-selected sample of BD binary systems, which can then be directly compared to similar samples of stellar binaries.

Open-access reader

About this research paper

What this paper is about

Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs (BDs) are poorly understood. The multiplicity properties and minimum mass of the BD mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 M ☉ and 0.034 M ☉ , and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field BD binaries known. The discovery of a population of such binaries indicates that BD binaries can robustly form at least down to masses of ∼0.02 M ☉ . Future microlensing surveys will measure a mass-selected sample of BD binary systems, which can then be directly compared to similar samples of stellar binaries.

Why it matters

OpenAlex reports 51 citations for this work. Citation counts describe recorded attention and do not establish research quality.

Key contribution

A contribution statement is not available in the OpenAlex record.

Method / approach

Method details are not available in the OpenAlex metadata.

Main findings

Findings are not separately available in the OpenAlex metadata.

Limitations

Limitations are not available in the OpenAlex metadata.

Applications

Application details are not available in the OpenAlex metadata.

Available abstract

Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs (BDs) are poorly understood. The multiplicity properties and minimum mass of the BD mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 M ☉ and 0.034 M ☉ , and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field BD binaries known. The discovery of a population of such binaries indicates that BD binaries can robustly form at least down to masses of ∼0.02 M ☉ . Future microlensing surveys will measure a mass-selected sample of BD binary systems, which can then be directly compared to similar samples of stellar binaries.

Key concepts: Gravitational microlensing, Brown dwarf, Physics, Astrophysics, Low Mass, Astronomy, Binary number, Population

Related papers

Back to paper searchBrowse research topicsOriginal source
MICROLENSING DISCOVERY OF A POPULATION OF VERY TIGHT, VERY LOW MASS BINARY BROWN DWARFS — Research Paper | ScholarLens