Van Biesbroeck 8

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Van Biesbroeck 8
Ophiuchus constellation map.png
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Ophiuchus
Right ascension 16h 55m 28.755s
Declination −08° 20′ 10.84″
Apparent magnitude (V) 9.048
Characteristics
Spectral type M6.5V
U−B color index 16.7
B−V color index 18.7
Astrometry
Proper motion (μ) RA: 3.160889 mas/yr
Dec.: -7.84639 mas/yr
Parallax (π) 154.96 ± 0.52[1] mas
Distance 21.05 ± 0.07 ly
(6.45 ± 0.02 pc)
Absolute magnitude (MV) 17.75[2]
Other designations
Gl 644 C , GJ 644 D , LHS  429

Van Biesbroeck 8 (vB 8, Gliese 644 C) is a low-luminosity star in the constellation Ophiuchus, cataloged in the 20th century (in 1961) by the astronomer George Van Biesbroeck. It is the smallest, faintest, and most separated component of the quintuple star system Gliese 644/643 — the richest stellar system in the immediate solar neighbourhood (d<10pc).[2][3] Classified as a red dwarf star, it is approximately 18.7 light years from our solar system and possesses about 9% of the mass of the Sun. In 1984, apparently erroneous information led to the belief that the first extra-solar "planet" (later deemed to possibly be a brown dwarf) was orbiting Van Biewsbroeck 8. The object, termed Van Biesbroeck 8b, was twice confirmed, but subsequent attempts to locate it were unsuccessful.

References[edit]

  1. ^ THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars)
  2. ^ a b Mazeh, Tsevi; Latham, David W.; Goldberg, Elad; Torres, Guillermo; Stefanik, Robert P.; Henry, Todd J.; Zucker, Shay; Gnat, Orly; Ofek, Eran O. (2001). "Studies of multiple stellar systems - IV. The triple-lined spectroscopic system Gliese 644". Monthly Notices of the Royal Astronomical Society 325: 343–357. arXiv:astro-ph/0102451. Bibcode:2001MNRAS.325..343M. doi:10.1046/j.1365-8711.2001.04419.x. 
  3. ^ Ségransan, D.; Delfosse, X.; Forveille, T.; Beuzit, J.-L.; Udry, S.; Perrier, C.; Mayor, M. (2000). "Accurate masses of very low mass stars. III. 16 new or improved masses". Astronomy and Astrophysics 364: 665–673. arXiv:astro-ph/0010585. Bibcode:2000A&A...364..665S. 

External links[edit]

Coordinates: Sky map 16h 55m 28.755s, −08° 20′ 10.84″