A naked-eye triple system with a nonaccreting black hole in the inner binary

@article{Rivinius2020ANT,
  title={A naked-eye triple system with a nonaccreting black hole in the inner binary},
  author={Th. Rivinius and Dietrich Baade and Petr Hadrava and Marianne Heida and R{\'o}bert Klement},
  journal={Astronomy \& Astrophysics},
  year={2020}
}
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 a B3 III star and an unseen companion in a circular orbit. The radial-velocity semi-amplitude of 61.3 km s−1 of the inner star and its minimum (probable) mass of 5.0 M⊙ (6.3 ± 0.7 M⊙) imply a mass of the unseen object of ≥4.2 M⊙ (≥5.0 ± 0.4 M⊙), that is, a black hole (BH). The spectroscopic time… 
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31 Citations

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References

SHOWING 1-10 OF 107 REFERENCES
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…
A Strategy to Search for an Inner Binary Black Hole from the Motion of the Tertiary Star
There are several on-going projects to detect a number of stars orbiting around invisible objects. A fraction of them may be a triple system consisting of an inner binary black hole (BBH) and an…
A 10-Day Binary System Orbiting the Be Star 66 Oph
66 Oph is a multiple system with a close binary orbiting the B2Ve primary Be star. The binary parameters were derived by two independent methods and spectra of components BA and BB were separated by…
Discovery of a Candidate Black Hole - Giant Star Binary System in the Galactic Field
We report the discovery of the first likely black hole in a non-interacting binary system with a field red giant. By combining radial velocity measurements from the Apache Point Observatory Galactic…
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…
Properties of OB star−black hole systems derived from detailed binary evolution models
Context. The recent gravitational wave measurements have demonstrated the existence of stellar mass black hole binaries. It is essential for our understanding of massive star evolution to identify…
A Be-type star with a black-hole companion
TLDR
Observations of an accretion disk line mirroring the orbit of MWC 656, the candidate counterpart of the γ-ray source AGL J2241+4454, indicates that a black hole of 3.8 to 6.9 solar masses orbits the star, implying that Be binaries with black-hole companions are difficult to detect in conventional X-ray surveys.
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.
Synthetic catalog of black holes in the Milky Way
Aims. We present an open-access database that includes a synthetic catalog of black holes (BHs) in the Milky Way, divided by the components disk, bulge, and halo. Methods. To calculate the evolution…
A noninteracting low-mass black hole–giant star binary system
A black hole hiding in a binary star As material falls toward a black hole, it heats up and emits x-rays. Almost all black holes are discovered by this x-ray emission. Thompson et al. observed light…
...
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