41 G. Arae

41 G. Arae
Observation data
Epoch J2000      Equinox J2000
Constellation Ara
Right ascension 17h 19m 03.83755s[1]
Declination −46° 38′ 10.4404″[1]
Apparent magnitude (V) 5.48[2] (5.61 / 8.88)[3]
Characteristics
Spectral type G8V + M0V[4]
U−B color index +0.38[5]
B−V color index +0.80[6]
R−I color index +0.41[6]
Astrometry
Radial velocity (Rv)25.96±0.14[1] km/s
Proper motion (μ) RA: 1029.610 mas/yr[1]
Dec.: 106.935 mas/yr[1]
Parallax (π)113.7513 ± 0.0725 mas[1]
Distance28.67 ± 0.02 ly
(8.791 ± 0.006 pc)
Absolute magnitude (MV)5.74[7]
Orbit[3]
Companion41 G. Ara B
Period (P)953 yr
Semi-major axis (a)13.341″
Eccentricity (e)0.825
Inclination (i)40.5°
Longitude of the node (Ω)137.3°
Periastron epoch (T)1907.5
Argument of periastron (ω)
(secondary)		329.7°
Details
41 G. Ara A
Mass0.810[8] M☉
Radius0.79[8] R☉
Luminosity0.42[citation needed] L☉
Surface gravity (log g)4.5[6] cgs
Temperature5,305[6] K
Metallicity [Fe/H]−0.35[6] dex
Rotational velocity (v sin i)4.5[9] km/s
Age5.5–6.3[10] Gyr
41 G. Ara B
Mass0.52[4] M☉
Radius0.650[4] R☉
Other designations
41 G. Arae, CD-46° 11370, GJ 666, HD 156274, HIP 84720, HR 6416, LHS 444, LTT 6886, SAO 227816, LPM 636, LFT 1334.
Database references
SIMBAD41 G. Ara
41 G. Ara A
41 G. Ara B
ARICNS41 G. Ara A
41 G. Ara B

41 G. Arae (abbreviated to 41 G. Ara), also known as GJ 666, is a trinary star system in the constellation Ara 28.7 light-years (8.8 parsecs) from the Sun. Although often called just 41 Arae, it is more accurate to call it 41 G. Arae, as the number 41 is the Gould designation (Flamsteed only covered the northern hemisphere).

The primary star in this system is a G-type main sequence star with a stellar classification of G8V. It has about 81% of the mass of the Sun, and 79% of the Sun's radius.[8] The fainter member of the pair, a red dwarf,[4] has a peculiar spectrum that shows a deficiency in elements with a higher atomic number than Helium. No planetary companions have been detected in orbit around these stars.[11]

The two stars share a highly elliptical orbit that takes several centuries to complete. The estimates of the period range from 693 to 2,200 years,[12] and the average separation of the two stars is about 210 AU (or 210 times the average distance between the Earth and the Sun).

41 G. Arae is most likely a triple, comprising the following components: Gliese 666A supposed as a spectroscopic binary, and Gliese 666B as its companion. Two other visual companions were proposed, but neither share the system's motion.[13] Observations from Gaia have shown that it is in fact component B which is binary, with an orbital period of 88 days.[14]

This system has a relatively high proper motion, moving over a second of arc across the sky each year. The space velocity components of this system are [U, V, W] = [+38, +30, −19] km/s.[6] The stars in this system show low chromospheric activity, and have a net space velocity of 52 km/s relative to the Sun. This, in combination with their low metallicity, shows that the pair belongs to the old disk population.[6]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ a b Cite error: The named reference orb was invoked but never defined (see the help page).
  4. ^ a b c d Zakhozhaj, V. A. (1979). "Nearest stars". Vestnik Khar'kovskogo Universiteta. 190. SIMBAD: 52–77. Bibcode:1979VKha..190...52Z.
  5. ^ Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J.
  6. ^ a b c d e f g Cite error: The named reference aaa191_2_237 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference apjss168_2_297 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference aaa493_3_1099 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference apj687_2_1264 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference aaa437_3_1127 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference ab6_2_308 was invoked but never defined (see the help page).
  13. ^ Jenkins, J. S.; Díaz, M.; Jones, H. R. A.; Butler, R. P.; Tinney, C. G.; O'Toole, S. J.; Carter, B. D.; Wittenmyer, R. A.; Pinfield, D. J. (2015). "The observed distribution of spectroscopic binaries from the Anglo-Australian Planet Search". Monthly Notices of the Royal Astronomical Society. 453 (2): 1439. arXiv:1507.04749. Bibcode:2015MNRAS.453.1439J. doi:10.1093/mnras/stv1596.
  14. ^ Cite error: The named reference Reyle2023 was invoked but never defined (see the help page).