5 Aurigae

5 Aurigae is a triple star^[7] system in the northern constellation of Auriga,^[10] located about 195 light years away from the Sun based on parallax.^[1] It is just visible to the naked eye as a dim, yellow-white hued star with an apparent visual magnitude of 5.95.^[2] The system is moving away from the Earth with a heliocentric radial velocity of +6 km/s,^[6] having come within 62.4 light-years some 8.7 million years ago.^[2]

5 Aurigae

Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	05h 00m 18.33887s[1]
Declination	+39° 23′ 40.9241″[1]
Apparent magnitude (V)	5.95[2] (6.02 + 9.50)[3]
Characteristics
Spectral type	F5 V[4]
U−B color index	−0.03[5]
B−V color index	+0.42[5]
Astrometry
Radial velocity (Rv)	+6.0±1.3[6] km/s
Proper motion (μ)	RA: −10.87[1] mas/yr Dec.: −1.08[1] mas/yr
Parallax (π)	16.74 ± 0.71 mas[1]
Distance	195 ± 8 ly (60 ± 3 pc)
Absolute magnitude (MV)	2.07[2]
Orbit[7]
Period (P)	1,598.04±50.35 yr
Semi-major axis (a)	5.379±0.388″
Eccentricity (e)	0.536±0.031
Inclination (i)	56.1±0.8°
Longitude of the node (Ω)	155.4±0.7°
Periastron epoch (T)	3,242.73±8.96
Argument of periastron (ω) (secondary)	333.4±4.5°
Details
5 Aur A
Mass	1.48[8] or 1.70[7] M☉
Luminosity	12.46[2] L☉
Surface gravity (log g)	4.14[8] cgs
Temperature	6,603±225[8] K
Metallicity [Fe/H]	−0.02±0.07[9] dex
Age	2.205[8] Gyr
5 Aur B
Mass	0.82[7] M☉
Other designations
BD+39° 1133, GC 6084, HD 31761, HIP 23261, HR 1599, SAO 57559, PPM 69817, ADS 3589, CCDM J05003+3924, WDS J05003+3924, TYC 2899-369-1[10]
Database references
SIMBAD	data

This was initially discovered to be a binary star system by Otto Struve. The outer pair has an orbital period of 1,598 years with an eccentricity of 0.536.^[7] The magnitude 6.02^[3] primary, component A, is itself a binary system consisting of two stars of similar mass, roughly 1.5 times the mass of the Sun each, with an orbital period of 8.08 years.^[11] It has a stellar classification of F5 V,^[4] matching an F-type main-sequence star.

As of 2017, component B is a magnitude 9.50 star at an angular separation of 4.10″ from the primary along a position angle of 285°.^[3]

References

1. van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
2. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
3. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
4. Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series. 176 (1): 216–217. Bibcode:2008ApJS..176..216A. doi:10.1086/525529.
5. Guetter, H. H. (1980). "UBV Photoelectric Photometry of 259 PZT Stars". Publications of the Astronomical Society of the Pacific. 92: 215. Bibcode:1980PASP...92..215G. doi:10.1086/130650.
6. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
7. Cvetkovic, Z.; Novakovic, B. (December 2006). "Orbits For Sixteen Binaries". Serbian Astronomical Journal. 173 (173): 73–82. Bibcode:2006SerAJ.173...73C. doi:10.2298/SAJ0673073C.
8. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
9. Gáspár, András; et al. (2016). "The Correlation between Metallicity and Debris Disk Mass". The Astrophysical Journal. 826 (2): 171. arXiv:1604.07403. Bibcode:2016ApJ...826..171G. doi:10.3847/0004-637X/826/2/171. S2CID 119241004.
10. "5 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-04-14.
11. Tokovinin, Andrei (2014). "From Binaries to Multiples. Ii. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 87. arXiv:1401.6827. Bibcode:2014AJ....147...87T. doi:10.1088/0004-6256/147/4/87. S2CID 56066740.

External links

• HR 1599
• CCDM J05003+3924
• Image 5 Aurigae