The Nearest Discovered Black Hole Is Likely Not in a Triple Configuration

@article{Safarzadeh2020TheND,
  title={The Nearest Discovered Black Hole Is Likely Not in a Triple Configuration},
  author={Mohammadtaher Safarzadeh and Silvia Toonen and Abraham Loeb},
  journal={The Astrophysical Journal Letters},
  year={2020},
  volume={897}
}
HR 6819 was recently claimed to be a hierarchical triple system of a Be star in a wide orbit around an inner binary system of a black hole (BH) and a B III type star. We argue that this system is unlikely to be a hierarchical triple for three reasons. (i) Given that this system is discovered in a magnitude-limited Bright Star Catalog, the expected number of such systems in the Milky Way (MW) amounts to about 104, while the estimate for the MW budget for such systems is between 102 and 103… 

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References

SHOWING 1-10 OF 29 REFERENCES
Tidal interactions in star cluster simulations
ABSTRA C T We describe the implementation of tidal circularization of binaries in an N-body code for star cluster simulations. The first part contains the theoretical framework for normal and chaotic
Predicting the binary black hole population of the Milky Way with cosmological simulations
Author(s): Lamberts, A; Garrison-Kimmel, S; Hopkins, PF; Quataert, E; Bullock, JS; Faucher-Giguere, CA; Wetzel, A; Keres, D; Drango, K; Sanderson, RE | Abstract: © 2018 The Author(s). Binary black
Detecting stars, galaxies, and asteroids with Gaia
(Abridged) Gaia aims to make a 3-dimensional map of 1,000 million stars in our Milky Way to unravel its kinematical, dynamical, and chemical structure and evolution. Gaia's on-board detection
The binarity of the local white dwarf population
Context As endpoints of stellar evolution, white dwarfs (WDs) are powerful tools to study the evolutionary history of the Galaxy. In particular, the multiplicity of WDs contains information
A naked-eye triple system with a nonaccreting black hole in the inner binary
Several dozen optical echelle spectra demonstrate that HR 6819 is a hierarchical triple. A classical Be star is in a wide orbit with an unconstrained period around an inner 40 d binary consisting of
On the signature of a 70-solar-mass black hole in LB-1
TLDR
It is shown that the apparent shifts of the Hα emission line used to derive the mass of the black hole arise from the orbital motion of the B-type companion star in the LB-1 binary system and not from that of theblack hole, removing the existing tension between its proposed existence and models of the formation of such a massive black hole at galactic metallicity.
Not so fast: LB-1 is unlikely to contain a 70 M⊙ black hole
The recently discovered binary LB-1 has been reported to contain a ${\sim }70\, \mathrm{M}_{\odot}$ black hole (BH). The evidence for the unprecedentedly high mass of the unseen companion comes
No signature of the orbital motion of a putative 70 solar mass black hole in LB-1.
Liu et al. (2019) recently reported the detection of a 68 [+11/-13] solar mass (Msun) black hole (BH) paired with an 8.2 [+0.9/-1.2] Msun B-type sub-giant star in the 78.9-day spectroscopic binary
Weighing in on black hole binaries with bpass: LB-1 does not contain a 70 M⊙ black hole
The recent identification of a candidate very massive 70 M(Sun) black hole is at odds with our current understanding of stellar winds and pair-instability supernovae. We investigate alternate
A wide star–black-hole binary system from radial-velocity measurements
TLDR
Radial-velocity measurements of a Galactic B-type star show a dark companion that seems to be a black hole of about 68 solar masses, in a widely spaced binary system.
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