Mu Herculis

Mu Herculis

Historical view of the Hercules constellation showing Mu Herculis (μ Her) as one of stars in the hero's elbow.
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
μ Her Aab (μ1 Her)
Right ascension 17h 46m 27.52667s[1]
Declination +27° 43′ 14.4379″[1]
Apparent magnitude (V) 3.417 ± 0.014[1]
μ Her BC (μ2 Her)
Right ascension 17h 46m 25.079s[2]
Declination +27° 43′ 01.45″[2]
Apparent magnitude (V) 10.2 / 10.7[3]
Characteristics
μ Her Aab
Spectral type G5IV[4] / M4V[5]
U−B color index +0.40[6]
B−V color index +0.76[6]
μ Her BC
Spectral type M3.5V[7]
U−B color index +1.00[6]
B−V color index +1.50[6]
Astrometry
μ Her Aab
Radial velocity (Rv)−17.07 ± 0.12[8] km/s
Proper motion (μ) RA: −291.66[1] mas/yr
Dec.: −749.60[1] mas/yr
Parallax (π)120.33 ± 0.16 mas[1]
Distance27.11 ± 0.04 ly
(8.31 ± 0.01 pc)
Absolute magnitude (MV)3.82 ± 0.02[8]
μ Her BC
Proper motion (μ) RA: −343.35[9] mas/yr
Dec.: −743.88[9] mas/yr
Parallax (π)119.8871 ± 0.2055 mas[10]
Distance27.21 ± 0.05 ly
(8.34 ± 0.01 pc)
Absolute magnitude (MV)+10.26[11]
Position (relative to μ Her Aab)[12]
Componentμ Her BC
Angular distance35″
Orbit[5]
Primaryμ Her Aa
Companionμ Her Ab
Period (P)98.9 ± 22.7 yr
Semi-major axis (a)2.9 ± 0.3″
Eccentricity (e)0.44 ± 0.06
Inclination (i)62.82 ± 4.66°
Longitude of the node (Ω)80.4 ± 1.7°
Periastron epoch (T)B 1921.1 ± 23.8
Argument of periastron (ω)
(secondary)		214 ± 16°
Semi-amplitude (K1)
(primary)		1.12 ± 0.10 km/s
Orbit[3]
Primaryμ Her B
Companionμ Her C
Period (P)43.127 ± 0.013 yr
Semi-major axis (a)1.385 ± 0.038″
Eccentricity (e)0.1796 ± 0.0009
Inclination (i)66.06 ± 0.15°
Longitude of the node (Ω)60.07 ± 0.17°
Periastron epoch (T)B 2008.335 ± 0.073
Argument of periastron (ω)
(secondary)		172.85 ± 0.64°
Details
μ Her Aa
Mass1.11 ± 0.01[8] M☉
Radius1.73 ± 0.02[8] R☉
Luminosity2.54 ± 0.08[8] L☉
Surface gravity (log g)3.98 ± 0.10[8] cgs
Temperature5560 ± 80[8] K
Metallicity [Fe/H]0.28 ± 0.07[8] dex
Rotation52+3
−1 d[8]
Rotational velocity (v sin i)1.7 ± 0.4[8] km/s
Age7.8+0.3
−0.4[8] Gyr
μ Her Ab
Mass0.32[5] M☉
μ Her B
Mass0.44[13] M☉
Radius0.60[14] R☉
Luminosity0.087[14] L☉
Temperature4,050[14] K
Metallicity [Fe/H]+0.21[14] dex
μ Her C
Mass0.39[13] M☉
Other designations
86 Herculis, Gl 695, HR 6623, BD+27° 2888, HD 161797, LHS 3326/3325, LTT 15266, SAO 85397, FK5 667, LFT 1374, GC 24138, ADS 10786, HIP 86974.[15]
Database references
SIMBADμ Her Aab
μ Her BC

Mu Herculis (μ Herculis) is a nearby quadruple star system about 27.1 light years from Earth in the constellation Hercules. Its main star, Mu Herculis A is fairly similar to the Sun although more highly evolved with a stellar classification of G5 IV. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[16] Its mass is about 1.1 times that of the Sun,[8] and it is beginning to expand to become a giant.

  1. ^ a b c d e f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b Cutri, R. M.; et al. (2003). "2MASS All-Sky Catalog of Point Sources". VizieR On-line Data Catalog. 2246. Bibcode:2003yCat.2246....0C.
  3. ^ a b "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 23 March 2017.
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  5. ^ a b c Roberts Jr., Lewis C.; Mason, Brian D.; Aguilar, Jonathan; Carson, Joseph; Crepp, Justin; Beichman, Charles; Brenner, Douglas; Burruss, Rick; Cady, Eric; Luszcz-Cook, Statia; Dekany, Richard; Hillenbrand, Lynne; Hinkley, Sasha; King, David; Lockhart, Thomas G.; Nilsson, Ricky; Oppenheimer, Rebecca; Parry, Ian R.; Pueyo, Laurent; Rice, Emily L.; Sivaramakrishnan, Anand; Soummer, Rémi; Vasisht, Gautam; Veicht, Aaron; Wang, Ji; Zhai, Chengxing; Zimmerman, Neil T. (2016). "Characterization of the Companion to μ Her". The Astronomical Journal. 151 (6): 169. arXiv:1604.06494. Bibcode:2016AJ....151..169R. doi:10.3847/0004-6256/151/6/169. S2CID 43403927.
  6. ^ a b c d Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data: 0. Bibcode:1986EgUBV........0M.
  7. ^ Alonso-Floriano, F. J.; Morales, J. C.; Caballero, J. A.; Montes, D.; Klutsch, A.; Mundt, R.; Cortés-Contreras, M.; Ribas, I.; Reiners, Ansgar; Amado, P. J.; Quirrenbach, A.; Jeffers, S. V. (2015). "CARMENES input catalogue of M dwarfs" (PDF). Astronomy & Astrophysics. 577: A128. arXiv:1502.07580. Bibcode:2015A&A...577A.128A. doi:10.1051/0004-6361/201525803. S2CID 53135130.[permanent dead link]
  8. ^ a b c d e f g h i j k l Grundahl, F.; Andersen, M. Fredslund; Christensen-Dalsgaard, J.; Antoci, V.; Kjeldsen, H.; Handberg, R.; Houdek, G.; Bedding, T. R.; Pallé, P. L.; Jessen-Hansen, J.; Aguirre, V. Silva; White, T. R.; Frandsen, S.; Albrecht, S.; Andersen, M. I.; Arentoft, T.; Brogaard, K.; Chaplin, W. J.; Harpsøe, K.; Jørgensen, U. G.; Karovicova, I.; Karoff, C.; Rasmussen, P. Kjærgaard; Lund, M. N.; Lundkvist, M. Sloth; Skottfelt, J.; Norup Sørensen, A.; Tronsgaard, R.; Weiss, E. (2017). "First Results from the Hertzsprung SONG Telescope: Asteroseismology of the G5 Subgiant Star μ Herculis". The Astrophysical Journal. 836 (1): 142. arXiv:1701.03365. Bibcode:2017ApJ...836..142G. doi:10.3847/1538-4357/836/1/142. S2CID 119480210.
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  10. ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  11. ^ Davison, Cassy L.; White, R. J.; Henry, T. J.; Riedel, A. R.; Jao, W. -C.; Bailey, J. I.; Quinn, S. N.; Cantrell, J. R.; Subasavage, J. P.; Winters, J. G. (2015). "A 3D Search for Companions to 12 Nearby M Dwarfs". The Astronomical Journal. 149 (3): 106. arXiv:1501.05012. Bibcode:2015AJ....149..106D. doi:10.1088/0004-6256/149/3/106. S2CID 9719725.
  12. ^ Cite error: The named reference Simbad2 was invoked but never defined (see the help page).
  13. ^ a b "Multiple Star Catalog". Archived from the original on 2018-12-03. Retrieved 2018-12-02.
  14. ^ a b c d Gaidos, E.; Mann, A. W.; Lépine, S.; Buccino, A.; James, D.; Ansdell, M.; Petrucci, R.; Mauas, P.; Hilton, E. J. (2014). "Trumpeting M dwarfs with CONCH-SHELL: A catalogue of nearby cool host-stars for habitable exoplanets and life". Monthly Notices of the Royal Astronomical Society. 443 (3): 2561. arXiv:1406.7353. Bibcode:2014MNRAS.443.2561G. doi:10.1093/mnras/stu1313.
  15. ^ Cite error: The named reference Simbad1 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference baas25_1319 was invoked but never defined (see the help page).