Furuhjelm 46

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Furuhjelm 46
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 17h 12m 07.91s
Declination +45° 39′ 57.2″
Apparent magnitude (V) 10.02/10.25
Characteristics
Spectral type M3 + M3.5
Astrometry
Radial velocity (Rv) –19 ± 5 km/s
Proper motion (μ) RA: +348.59 ± 5.68 mas/yr
Dec.: –1624.84 ± 6.80 mas/yr
Parallax (π) 167.29 ± 5.02 mas
Distance 19.5 ± 0.6 ly
(6.0 ± 0.2 pc)
Orbit[1]
Period (P) 12.9512 ± 0.0096 yr
Semi-major axis (a) 0.7620 ± 0.0015"
Eccentricity (e) 0.7430 ± 0.008
Inclination (i) 149.14 ± 0.25°
Longitude of the node (Ω) 160.0 ± 1.3°
Periastron epoch (T) 1991.032 ± 0.011[2]
Argument of periastron (ω)
(secondary)
99.0 ± 1.0°
Details
Temperature 3,272 ± 28[3] K
Metallicity [Fe/H] –0.31 ± 0.17[3] dex
Other designations
BD+45° 2505, HD 155876, HIP 84140, WDS 17121+5450, KUI 79
Gl 661 A: LFT 1326, LTT 15095, LHS 433, NLTT 44362
Gl 661 B: LFT 1327, LTT 15096, LHS 434, NLTT 44363

Furuhjelm 46, also known as HD 155876 and Gliese 661, is a nearby binary star system, consisting of two very similar red dwarfs, located in the constellation Hercules.

Furuhjelm 46 is the nearest "true" (i. e. not brown dwarf) star system in Hercules, however, there is brown dwarf in this constellation, located closer: WISE 1741+2553.

References[edit]

  1. ^ From the Sixth Catalog of Orbits of Visual Binary Stars, based upon Hartkopf, W. I.; Mason, B. D.; McAlister, H. A. (1996), "Binary star orbits from speckle interferometry. VIII. Orbits of 37 close visual systems", Astronomical Journal 111: 370–392, Bibcode:1996AJ....111..370H, doi:10.1086/117790 
  2. ^ Fractional Besselian year.
  3. ^ a b Rojas-Ayala, Bárbara et al. (April 2012). "Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs". The Astrophysical Journal 748 (2): 93. arXiv:1112.4567. Bibcode:2012ApJ...748...93R. doi:10.1088/0004-637X/748/2/93. 

See also[edit]

Furuhjelm 46 at the SIMBAD Astronomical Database.

External links[edit]