41 G. Arae

Last updated
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]
Distance 28.67 ± 0.02  ly
(8.791 ± 0.006  pc)
Absolute magnitude  (MV)5.74 [7]
Orbit [8]
Primary41 G. Ara A
Companion41 G. Ara B
Period (P)954.2±68.7 yr
Semi-major axis (a)12.752″ ±0.548″
(112 AU) [a]
Eccentricity (e)0.816±0.007
Inclination (i)35.2±0.8°
Longitude of the node (Ω)150.3±1.3°
Periastron epoch (T)1908.2±0.28
Argument of periastron (ω)
(secondary)		320.2±2.5°
Semi-amplitude (K1)
(primary)		1.956±0.068 km/s
Orbit [8]
Primary41 G. Ara Ba
Companion41 G. Ara Bb
Period (P)0.24069 yr
Semi-major axis (a)0.0410″ ±0.0024″
(0.36 AU) [b]
Eccentricity (e)0.773
Inclination (i)57.9±4.9°
Longitude of the node (Ω)170.6±3.1°
Periastron epoch (T)2015.903±0.012
Argument of periastron (ω)
(secondary)		242.2±14.8°
Details
41 G. Ara A
Mass 0.87 [8]   M☉
Radius 0.79 [9]   R☉
Luminosity 0.42[ citation needed ]  L☉
Surface gravity (log g)4.5 [6]   cgs
Temperature 5,305 [6]   K
Metallicity [Fe/H]−0.35 [6]   dex
Rotational velocity (v sin i)4.5 [10]  km/s
Age 5.5–6.3 [11]   Gyr
41 G. Ara Ba
Mass 0.60 [8]   M☉
Radius 0.650 [4]   R☉
41 G. Ara Bb
Mass 0.42 [8]   M☉
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
SIMBAD 41 G. Ara
41 G. Ara A
41 G. Ara B
ARICNS 41 G. Ara A
41 G. Ara B

41 G. Arae (abbreviated to 41 G. Ara), also known as Gliese 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 and not the Flamsteed designation.

Contents

Characteristics

41 G. Arae is a hierarchical triple star system, made up of an outer pair, 41 G. Arae A and B, and an inner pair, 41 G. Arae Ba and Bb. [12] Two other visual companions were proposed, but neither share the system's motion. [13] 41 G. Arae A and B share a highly eccentric orbit that takes around a millenium to complete. Their semi-major axis is of 110 astronomical units. [a] As of 2025, the last periastron was in 1908. [8]

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. [9]

The secondary component of the outer binary, 41 G. Arae B, is a pair of red dwarfs that complete an orbit around each other every 88 days, [12] and are also in an eccentric orbit. [8] 41 G. Arae Ba and Bb have masses of 0.60 and 0.41 solar masses, respectively. [8] It has a peculiar spectrum that shows a deficiency in elements with a higher atomic number than helium. [14]

Motion

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]

See also

Notes

  1. 1 2 Calculated using the distance of 8.791 parsecs [1] and the separation of 12.752 arcseconds. [8] 8.791  • 12.752 = 112 AU.
  2. ↑ Calculated using the distance of 8.791 parsecs [1] and the separation of 0.0410 arcseconds. [8] 8.791  • 0.041 = 0.36 AU.

References

  1. 1 2 3 4 5 6 7 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  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. ↑ "Entry 171903.85-463810.1", Sixth Catalog of Orbits of Visual Binary Stars, United States Naval Observatory, archived from the original on 2017-08-01, retrieved 2016-06-07.
  4. 1 2 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. 1 2 3 4 5 6 7 Perrin, M.-N.; de Strobel, G. Cayrel; Dennefeld, M. (1988), "High S/N detailed spectral analysis of four G and K dwarfs within 10 PC of the sun", Astronomy and Astrophysics, 191 (2): 237–247, Bibcode:1988A&A...191..237P
  7. ↑ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv: 0811.3982 , Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID   118577511.
  8. 1 2 3 4 5 6 7 8 9 Tokovinin, Andrei (2025), "Orbits of Six Triple Systems", The Astronomical Journal, 169 (3): 124, arXiv: 2501.04807 , Bibcode:2025AJ....169..124T, doi: 10.3847/1538-3881/ada3c6
  9. 1 2 Takeda, G.; et al. (February 2007) [2006], "Structure and Evolution of Nearby Stars with Planets II. Physical Properties of ~ 1000 Cool Stars from the SPOCS Catalog", The Astrophysical Journal Supplement Series, 168 (2): 297–318, arXiv: astro-ph/0607235 , Bibcode:2007ApJS..168..297T, doi:10.1086/509763, S2CID   18775378
  10. ↑ Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi: 10.1051/0004-6361:200810377 [ permanent dead link ]
  11. ↑ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv: 0807.1686 , Bibcode:2008ApJ...687.1264M, doi:10.1086/591785, S2CID   27151456
  12. 1 2 Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (6 February 2023). The 10 parsec sample in the Gaia era: First update. The 21st Cambridge workshop on Cool Stars, Stellar Systems, and the Sun. arXiv: 2302.02810 . doi:10.5281/zenodo.7576096.
  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. ↑ Santos, N. C.; et al. (July 2005), "Spectroscopic metallicities for planet-host stars: Extending the samples", Astronomy and Astrophysics, 437 (3): 1127–1133, arXiv: astro-ph/0504154 , Bibcode:2005A&A...437.1127S, doi:10.1051/0004-6361:20052895, S2CID   16256304
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