Hubble Space Telescope Observations of Binary Very Low Mass Stars and Brown Dwarfs

By J. Gizis, I. Neill Reid, G. Knapp, J. Liebert, J. D. Kirkpatrick, D. Koerner, A. Burgasser. 2003

166 citations recorded by the source corpus.

We present analysis of Hubble Space Telescope (HST) images of 82 nearby field late M and L dwarfs. We resolve 13 of these systems into double M/L dwarf systems and identify an additional possible binary. Combined with previous observations of 20 L dwarfs, we derive an observed binary fraction for ultracool dwarfs of 17%, where the statistics included systems with separations in the range 1.6–16 AU. We argue that accounting for biases and incompleteness leads to an estimated binary fraction 15% ± 5% in the range 1.6–16 AU. No systems wider than 16 AU are seen, implying that the wide companion frequency is less than 1.7%; the distribution of orbital separation is peaked at ∼2–4 AU and differs greatly from the G dwarf binary distribution. Indirect evidence suggests that the binary fraction is ∼5% ± 3% for separations less than 1.6 AU. We find no evidence for differences in the binary fraction between stellar late M and L dwarfs and substellar L dwarfs. We note, however, that the widest (greater than 10 AU) systems in our sample are all of earlier (M8–L0) spectral type; a larger sample is needed to determine if this is a real effect. One system with a spectral type of L7 has a secondary that is fainter in the HST F814W filter but brighter in F1042M; we argue that this secondary is an early T dwarf.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/78ae2c9a2ead06a103a20823537e45431d823390

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In Astronomy and Astrophysics

1. Michael C. Liu
2. A. Burgasser
3. J. D. Kirkpatrick
4. T. Dupuy
5. K. Luhman
6. Kelle Cruz
7. M. Marley
8. K. Allers

In Instrumentation

1. Michael C. Liu
2. A. Burgasser
3. J. D. Kirkpatrick
4. T. Dupuy
5. K. Luhman
6. Kelle Cruz
7. M. Marley
8. K. Allers

Citations in the corpus

• Preliminary Parallaxes of 40 L and T Dwarfs from the US Naval Observatory Infrared Astrometry Program (2004, methodology): “Gizis et al. (2003) found this to be a binary with 0.13 arcsec separation using the HST WFPC2 camera.”
• THE 0.8–14.5 μm SPECTRA OF MID-L TO MID-T DWARFS: DIAGNOSTICS OF EFFECTIVE TEMPERATURE, GRAIN SEDIMENTATION, GAS TRANSPORT, AND SURFACE GRAVITY (2009, background): “This brightening is a real effect and not due to variations in other parameters as verified by several studies of binary systems (Gizis et al. 2003, Cruz et al. 2004, Burgasser et al. 2006b, Liu et al. 2006, Looper et al. 2008).”
• THE HAWAII INFRARED PARALLAX PROGRAM. II. YOUNG ULTRACOOL FIELD DWARFS (2016, background): “The vast majority of our field ultracool sample (both our CFHT targets and the literature objects described in Section 2.5.2) have been imaged at high angular resolution, either with HST (e.g. Bouy et al. 2003; Gizis et al. 2003) or with Keck LGS AO by us.”
• New spectral types L and T (2005, unknown): “…2003 1 0 2MASSI J0144353 − 071614 Burgasser et al. 2003c 0 1 2MASS J15031961 + 2525196 Scholz et al. 2003 0 1 Ind B Salim et al. 2003 1 0 LSR 0602 + 3910 Gizis et al. 2003 3 0 more 2MASS L dwarfs Kendall et al. 2003 7 0 more 2MASS L dwarfs Wilson et al. 2003 10 0 more 2MASS L dwarfs Berriman et…”
• Multiplicity of Nearby Free-floating Ultracool Dwarfs: A Hubble Space Telescope WFPC2 Search for Companions (2003, methodology): “…(HST) and/or adaptive optics led to the discovery of a significant number of binaries (Martı́n et al. 1997, 1999a, 2000a; Koerner et al. 1999; Reid et al. 2001; Neuhäuser et al. 2002; Close et al. 2002a, 2002b; Potter et al. 2002; Burgasser et al. 2003; Gizis et al. 2003; Close et al. 2003).”
• THE ASTRALUX LARGE M-DWARF MULTIPLICITY SURVEY (2012, background): “For even later-type objects in the VLM range (very low mass stars and brown dwarfs), the multiplicity frequencies are as low as ∼10%–30% (e.g., Bouy et al. 2003; Close et al. 2003; Gizis et al. 2003; Joergens 2008).”
• BANYAN. VII. A NEW POPULATION OF YOUNG SUBSTELLAR CANDIDATE MEMBERS OF NEARBY MOVING GROUPS FROM THE BASS SURVEY (2015, background): “2MASS J23310161–0406193 (Koenigstuhl 3 BC) was discovered by Gizis et al. (2000) as an M9 dwarf in the optical, and Gizis et al. (2003) demonstrated that it is an M8 + L3, 0.”
• How Dry is the Brown Dwarf Desert? Quantifying the Relative Number of Planets, Brown Dwarfs, and Stellar Companions around Nearby Sun-like Stars (2004, background): “However, McCarthy & Zuckerman (2004) in their observation of 280 GKM stars find only 1 brown dwarf between 75 and 1200 AU. Gizis et al. (2 003) reports that 15% ± 5% of M/L dwarfs are brown dwarf binaries with separations in the range 1.6 16 AU. This falls to 5% ± 3% of M/L dwarfs with separations ”
• Spitzer IRAC Photometry of M, L, and T Dwarfs (2006, unknown): “…SDS 0423 0414, 2MA 0746+2000,GJ337CD,SDS0926+5847,SDS1021 0304,Kelu-1, 2MA1225 2739, 2MA1534 2952, 2MA1553+1532, and 2MA 1728+3948 (Reid et al. 2001; Burgasser et al. 2003b, 2005a, 2005b, 2006b; Gizis et al. 2003; Bouy et al. 2004; Golimowski et al. 2004b; Vrba et al. 2004; Liu&Leggett 2005).”
• New Brown Dwarfs and an Updated Initial Mass Function in Taurus (2004, background): “For types later than M8, the observed binary fraction of 15% (Reid et al. 2001; Bouy et al. 2003; Burgasser et al. 2003; Close et al. 2003; Gizis et al. 2003) can be reasonably described as a natural extension of the decreasing binary fraction with primary mass evident among field stars,…”
• THE HAWAII INFRARED PARALLAX PROGRAM. I. ULTRACOOL BINARIES AND THE L/T TRANSITION, (2012, background): “…(2010); (27) Forveille et al. (2005); (28) Freed et al. (2003); (29) Gelino et al. (2006); (30) Gelino et al. (2011); (31) Gizis & Reid (2000); (32) Gizis et al. (2003); (33) Golimowski et al. (1998); (34) Golimowski & Schroeder (1998); (35) Golimowski et al. (2004b); (36) Greissl et al. (2007);…”
• ε Indi Ba,Bb: The nearest binary brown dwarf (2003, background): “…brown dwarf binary was found in the solar neighbourhood by Mart´ın et al. (1999) and, subsequently, high spatial resolution imaging has identified a significant number of such systems (e.g., Close et al. 2002a; Goto et al. 2002; Potter et al. 2002; Gizis et al. 2003; Close et al. 2003).”
• Hubble Space Telescope NICMOS Observations of T Dwarfs: Brown Dwarf Multiplicity and New Probes of the L/T Transition (2006, background): “This is similar to resolved binary fractions measured for other large high resolution imaging samples of VLM field dwarfs (Reid et al. 2001, 2006a; Bouy et al. 2003; Close et al. 2003; Gizis et al. 2003; Siegler et al. 2005).”
• Giant Planet Companion to 2MASSW J1207334-393254 (2005, background): “2M1207A and b is very different from known brown dwarf binaries discovered in the field (Close et al. 2003, Gizis et al. 2003, Burgasser et al. 2003, Bouy et al. 2003) and within star forming regions (Neuhäuser et al. 2002), which are characte - ized by semi-major axes< 15 AU and a trend toward…”
• SpeX SPECTROSCOPY OF UNRESOLVED VERY LOW MASS BINARIES. I. IDENTIFICATION OF 17 CANDIDATE BINARIES STRADDLING THE L DWARF/T DWARF TRANSITION (2009, background): “…binaries include the six sources listed in Table 3 plus 2MASS J0850+1057 (Reid et al. 2001b; Dahn et al. 2002), 2MASS J0920+3517 (Reid et al. 2001b; Burgasser et al. 2006b), 2MASS J1728+3948 (Gizis et al. 2003), ǫ Indi BC (McCaughrean et al. 2004), and Gliese 337CD (Burgasser et al. 2005a).”